Journal articles: 'Dynamic elastic modulus'

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Abe, Y., P. Lambrechts, S. Inoue, M. J. A. Braem, M. Takeuchi, G. Vanherle, and B. Van Meerbeek. "Dynamic elastic modulus of ‘packable’ composites." Dental Materials 17, no. 6 (November 2001): 520–25. http://dx.doi.org/10.1016/s0109-5641(01)00012-4.

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Tang, Yan Jun, You Ming Li, Guo Xin Xue, Yu Zhao, Xiu Mei Zhang, and Yong Zhang. "Effect of Carboxylated Styrene-Butadiene Rubber Latex Amount on the Viscoelastic Behavior of Paper Coating Modified with Nanosized Particles." Advanced Materials Research 236-238 (May 2011): 1322–25. http://dx.doi.org/10.4028/www.scientific.net/amr.236-238.1322.

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The focus of this study is to investigate the effect of carboxylated styrene-butadiene rubber (SBR) latex on the dynamic rheologcial properties of paper coating suspensions modified with nanosized particles. The elastic storage modulus G′ and the viscid loss modulus G′′ are used to evaluate the dynamic rheologcial properties of paper coating suspensions. The effects of different amount carboxylated styrene-butadiene rubber latex on the flow parameters of paper coating suspensions are comparatively presented. It is shown that the dynamic elastic storage modulus G′ and viscid loss modules G′′ of paper coating suspensions increase with the SBR content change from 13% to 18%. The dynamic rheologcial properties are related to the strength of the network structure of paper coating suspensions. It is also found that the elastic storage modulus G′ of paper coating suspensions is larger than viscid loss modulus G′′, which indicates that paper coating suspensions in this investigation all behave like a viscoelastic solid.

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Gao, Xiao Peng, and Fu Shun Liu. "The Study of Ultrasonic Dynamic Elastic Modulus of TiNiFe Shape Memory Alloy in Heating Process." Advanced Materials Research 79-82 (August 2009): 1699–702. http://dx.doi.org/10.4028/www.scientific.net/amr.79-82.1699.

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The phase transformation characteristics, the dynamic elastic modulus and the static tensile elastic modulus of Ti50Ni47.5Fe2.5 alloy were investigated. It is found that, the two mutations in the dynamic elastic modulus is caused by reverse martensite phase transformation and austenite phase transformation respectively; Static tensile test can not reflect the intrinsic elastic modulus when the test temperature is close to martensite transformation temperature(Ms). The static elastic modulus and the dynamic elastic modulus have the same trend when the test temperature is enough higher than Ms.

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Chen, Depeng, Jiajia Zou, Liang Zhao, Shidai Xu, Tengfei Xiang, and Chunlin Liu. "Degradation of Dynamic Elastic Modulus of Concrete under Periodic Temperature-Humidity Action." Materials 13, no. 3 (January 30, 2020): 611. http://dx.doi.org/10.3390/ma13030611.

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Cracks caused by environmental temperature and humidity variation are generally considered one of the most important factors causing durability deterioration of concrete structures. The seasonal or daily variation of ambient temperature and humidity can be considered periodic. The dynamic modulus of elasticity is an important parameter used to evaluate the performance of structural concrete under periodic loads. Hence, in this paper, the dynamic elastic modulus test of concrete under simulating periodic temperature-humidity variation is carried out according to monthly meteorological data of representative areas (Nanjing, China). The dynamic elastic modulus attenuation pattern and a dynamic elastic modulus degradation model of concrete under periodic temperature-humidity are investigated. The test results show that the dynamic elastic modulus of concrete decreases and tends to be stable under the action of periodic temperature-humidity. Comparative analysis shows that the two-parameter dynamic elastic modulus degradation model is more suitable for describing the dynamic elastic modulus attenuation pattern of concrete under periodic temperature-humidity action than the single-parameter one.

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Huang, Dong Hui, Sheng Xing Wu, Xiao Jun Wang, and Hai Tao Zhao. "Effect of Admixtures on Dynamic Elastic Modulus of Cement Paste at Early Age." Advanced Materials Research 261-263 (May 2011): 450–55. http://dx.doi.org/10.4028/www.scientific.net/amr.261-263.450.

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The elastic modulus of cement paste is the key parameter for characterizing the mechanical response of concrete. In modern concrete technology, the admixtures are often used to enhance the performance of concrete. This paper introduces a nondestructive testing method to evaluate the dynamic elastic modulus of cement paste. Moreover, the effect of water-cement ratio and conventional admixtures on the dynamic elastic modulus of cement paste is investigated, in which three kinds of admixtures are taken into account including Viscosity Modifying Admixture (VMA), Silica Fume (SF), and Shrinkage-Reducing Admixture (SRA). The results from experimental investigation indicate that the dynamic elastic modulus of cement paste increases with decreasing water-cement ratio. The addition of SF increases the dynamic elastic modulus, however, the overdosage of VMA causes its reduction. SRA reduces the elastic modulus at early age without affecting the elastic modulus at later period.

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Zhu, Fang Zhi, Tie Jun Zhao, and Ting Guan. "Influence of Water Content on Dynamic Elastic Modulus of Concrete." Applied Mechanics and Materials 351-352 (August 2013): 1605–9. http://dx.doi.org/10.4028/www.scientific.net/amm.351-352.1605.

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Water content is one of key effect factors on the dynamic elastic modulus, which is an important damage assessment index of concrete structures induced by freeze-thaw cycles, fire and chemical attacks. Through the ultrasonic and bending vibration test, the regularity of dynamic elastic modulus changed with the water content of concrete specimens was analyzed in this paper. The results show that the ultrasonic velocity has a low sensitivity to water content when it is below 1.5%. The bending vibration method can better reflect the effect of water content change on dynamic elastic modulus. The regression equation of dynamic elastic modulus and water content was set up by introducing the index function. The research results offer technical reference for the predicting of actual concrete dynamic elastic modulus in different humidity environment.

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Yang, Guang Qing, Xi Zhao Wang, and Bao Jian Zhang. "Dynamic Characterization of Cement-Treated High-Speed Railway Subgrade." Advanced Materials Research 250-253 (May 2011): 3909–12. http://dx.doi.org/10.4028/www.scientific.net/amr.250-253.3909.

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In order to ensure the high-speed railway train running safety and stabilization, the subgrade should keep adequate strength, rigidity and long-term stabilization under the repeated train load. When the subgrade soil is poor, we can treat it with cement. Whether the performance of cement-treated soil can meet the demand of high-speed railway, so the dynamic triaxial test of cement-treated soil is studied in this paper. The dynamic performance of cement-treated soil under repeated train load is analyzed. The variation and influence factors of critical dynamic stress, accumulated plastic strain, elastic strain and resilient module of cement-treated soil are studied.When the dynamical stress more than the critical dynamical stress, the cumulate plastic strain and the elastic strain will rapidly increase with the increase of the loading time of the dynamical stress. The resilience modulus will decrease along with the increase of the dynamical stress. When the dynamical stress less than the he critical dynamical stress, the elastic strain and the resilience modulus remain constant with the increase of the loading time of the dynamical stress. And the elastic strain and the resilience modulus linearly increase with the increase of the dynamical stress.

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Omovie, Sheyore John, and John P. Castagna. "Relationships between Dynamic Elastic Moduli in Shale Reservoirs." Energies 13, no. 22 (November 17, 2020): 6001. http://dx.doi.org/10.3390/en13226001.

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Sonic log compressional and shear-wave velocities combined with logged bulk density can be used to calculate dynamic elastic moduli in organic shale reservoirs. We use linear multivariate regression to investigate modulus prediction when shear-wave velocities are not available in seven unconventional shale reservoirs. Using only P-wave modulus derived from logged compressional-wave velocity and density as a predictor of dynamic shear modulus in a single bivariate regression equation for all seven shale reservoirs results in prediction standard error of less than 1 GPa. By incorporating compositional variables in addition to P-wave modulus in the regression, the prediction standard error is reduced to less than 0.8 GPa with a single equation for all formations. Relationships between formation bulk and shear moduli are less well defined. Regressing against formation composition only, we find the two most important variables in predicting average formation moduli to be fractional volume of organic matter and volume of clay in that order. While average formation bulk modulus is found to be linearly related to volume fraction of total organic carbon, shear modulus is better predicted using the square of the volume fraction of total organic carbon. Both Young’s modulus and Poisson’s ratio decrease with increasing TOC while increasing clay volume decreases Young’s modulus and increases Poisson’s ratio.

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Zhao, Jian Bin, Ying Chun Ji, Xiao Liu, and Di Li. "Experimental Study on Dynamic Characteristics of Tailings." Applied Mechanics and Materials 580-583 (July 2014): 455–59. http://dx.doi.org/10.4028/www.scientific.net/amm.580-583.455.

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In this paper, the dynamic characteristics for three different kinds of copper tailings are studied through a series of cyclic triaxial tests. It is found that under confining pressure 200 and 300 kPa, elastic modulus raises with the increasement of coarse grain content to a certain degree and then declines, and the maximum elastic modulus corresponds to good gradation. While, as for confining pressure 100 kPa, elastic modulus raises with the increasement of fine grain content. It is also found that elastic modulus raises with the increasement of confning pressure. And, damping ratio raises with the increasement of shear strain and finally to a stable value. Finally, the fitting Gd/Gdmax~ curve for three kinds of tailings shows the reasonableness of test results.

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Abooalizadeh, Zahra, Leszek Josef Sudak, and Philip Egberts. "Nanoscale spatial mapping of mechanical properties through dynamic atomic force microscopy." Beilstein Journal of Nanotechnology 10 (July 3, 2019): 1332–47. http://dx.doi.org/10.3762/bjnano.10.132.

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Dynamic atomic force microscopy (AFM) was employed to spatially map the elastic modulus of highly oriented pyrolytic graphite (HOPG), specifically by using force modulation microscopy (FMM) and contact resonance (CR) AFM. In both of these techniques, a variation in the amplitude signal was observed when scanning over an uncovered step edge of HOPG. In comparison, no variation in the amplitude signal was observed when scanning over a covered step on the same surface. These observations qualitatively indicate that there is a variation in the elastic modulus over uncovered steps and no variation over covered ones. The quantitative results of the elastic modulus required the use of FMM, while the CR mode better highlighted areas of reduced elastic modulus (although it was difficult to convert the data into a quantifiable modulus). In the FMM measurements, single atomic steps of graphene with uncovered step edges showed a decrease in the elastic modulus of approximately 0.5%, which is compared with no change in the elastic modulus for covered steps. The analysis of the experimental data taken under varying normal loads and with several different tips showed that the elastic modulus determination was unaffected by these parameters.

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Zhou, Jingjing, Fasuo Zhao, Yanbo Zhu, Wenqi Dong, and Ziguang He. "Dynamic Behavior and Constitutive Relationship of Mudstone Slip Zone of Landslide with Weak Interlayer." Shock and Vibration 2021 (August 26, 2021): 1–13. http://dx.doi.org/10.1155/2021/3330127.

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Sliding zone dynamics in the Qinling-Daba mountain area under different dynamic parameters have not been studied extensively. In this study, we investigated the dynamic behavior of the sliding zones of a high-steep rock landslide in the Qinling-Daba mountain area under the influence of dynamic stress amplitude and frequency and proposed an empirical model of the dynamic constitutive relationship. The dynamic behavior was studied based on a cyclic triaxial test system. The results indicated that an increase in the dynamic stress amplitude decreased the dynamic elastic modulus linearly, increased the damping ratio, and increased the axial strain exponentially. Among these properties, the elastic strain was found to be more sensitive to the increase in the dynamic stress amplitude than the plastic strain. As the loading frequency increased, the dynamic elastic modulus increased, whereas the damping ratio decreased. Furthermore, the proposed empirical model of the dynamic constitutive relationship between the vibration number and loading frequency based on the dynamic elastic modulus could satisfactorily describe the dynamic stress-strain relationships of the samples from test stability and failure zones. These findings are expected to make a significant contribution toward further revealing the sliding mechanism of such landslides.

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Choubane, Bouzid, Chung-Lung Wu, and Mang Tia. "Coarse Aggregate Effects on Elastic Moduli of Concrete." Transportation Research Record: Journal of the Transportation Research Board 1547, no. 1 (January 1996): 29–34. http://dx.doi.org/10.1177/0361198196154700105.

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The results of a laboratory testing program carried out to investigate the effect of coarse aggregate types on the elastic modulus of typical pavement concretes are presented. The elastic modulus was determined in both flexure and compression using static and dynamic means. Three different mixes, made using three different aggregates, were compared. The water-cement ratio was kept at 0.53 throughout the test program. The results showed that within the tested range, the aggregate type significantly affected the studied properties of concrete. Calera aggregate (a dense limestone) with its rough-textured surface and angular shape produced a concrete with higher strength and stiffness than those of concretes made with Brooksville aggregate (a porous limestone) and river gravel. In addition, the measured dynamic modulus in compression was significantly different from that in flexure. Also, in flexure, the dynamic modulus was higher than the static modulus by an average of 23 percent, whereas in compression, the dynamic modulus appeared to be in the same range as the static modulus. The change in frequency from 1 to 7 Hz did not have a significant influence on the dynamic modulus.

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Zhang, Yong, Li Wan, and Xiong Wei Li. "The Deformation Characteristics of Soft Clay under Cyclic Loading." Advanced Materials Research 446-449 (January 2012): 1709–12. http://dx.doi.org/10.4028/www.scientific.net/amr.446-449.1709.

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Through the undrained dynamic triaxial experiment, the deformation characteristics of saturated soft clay under cyclic loading are investigated. The cyclic loading was simplified as sine wave. It is found that under different dynamic stress, the deformation patterns of specimen in this experiment can be divided into three kinds, such as dense compressed, tensile break-up and shear failure type. In the process of vibration, the deformation forms of samples can also be divided into three types by dynamic stress amplitude, such as stable, destructive and critical type. The dynamic stress amplitude corresponding to the critical type is called critical dynamic stress. With the dynamic elastic strain increasing gradually, the dynamic elastic modulus decreases and rigidity softening occurs. Furthermore, dynamic elastic modulus and dynamic elastic strain curve decrease while the cyclic number is increasing. Finally, to establish the equation of the relationship between dynamic elastic modulus and dynamic elastic strain, the factor of cycle number should be considered.

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Xie, Wenbo, Zi Wang, Zhiqiang Zhang, and Zheng Wang. "Dynamic test of laminated veneer lumber elastic modulus and its probability distribution." BioResources 16, no. 2 (March 19, 2021): 3318–27. http://dx.doi.org/10.15376/biores.16.2.3318-3327.

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The vibrational frequency method was used to measure the elastic modulus of laminated veneer lumber (LVL), and the feasibility of using Weibull distribution to analyze the elastic modulus data of LVL was considered. Samples were randomly selected as test pieces at the factory. The sponge support structure was used to realize the free beam state, and the modal test results verified the accuracy of realizing the free beam. Under transient excitation, the elastic modulus of the specimen was obtained by testing the first-order bending frequency. The Weibull distribution fitting test, Weibull distribution K-S test, and normal distribution K-S test were used for the test data. The probability of LVL elastic modulus was calculated under a given value. The results showed that the LVL elastic modulus did not obey the two-parameter Weibull distribution (Eu=0). The LVL elastic modulus fit to the three-parameter Weibull distribution (Eu) was greater than half of the minimum test value and the normal distribution. When 9 GPa and 8 GPa were used as the setting values of Eu, the calculated probability value was relatively stable. At this time, Eu was 81% and 92% of the minimum elastic modulus 9.815 GPa. Therefore, it was recommended to use 80% to 90% of the minimum value of the measured data as the setting value of the position parameter Eu. The three-parameter Weibull distribution and the normal distribution calculated LVL elastic modulus have the same probability under the given value.

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Qiu, Yan, Yi Wang Bao, Xiao Gen Liu, Xiu Fang Wang, and Kun Ming Li. "Comparison and Relative Error of Elastic Modulus in Glass Measured by Three Test Techniques." Key Engineering Materials 434-435 (March 2010): 209–13. http://dx.doi.org/10.4028/www.scientific.net/kem.434-435.209.

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Elastic modulus of glass was measured using static method, dynamic method and Vickers indentation technique, respectively. The residual indent of Vickers indentation is analyzed to estimate the elastic modulus, using conventional hardness tester without load-depth curve. The modulus and hardness of glass are determined by load, deformation and residual semi-angle of the indent. The result is compared with the modulus obtained by conventional dynamic and static methods. It was shown that the modulus measured by dynamic method provides the highest value and the modulus obtained by indentation technique is between the values of dynamic modulus and static modulus. The result also shows that the modulus measured by dynamic method has very stable value and that measured by bending method has the lowest value. The modulus obtained in indentation tests shows relatively greater scatter.

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Yin, Shui Ping, and Min Yu. "Dynamic Visco-Elastic Properties of Polycarbonate (PC) under Static and Dynamic Load." Advanced Materials Research 146-147 (October 2010): 1090–93. http://dx.doi.org/10.4028/www.scientific.net/amr.146-147.1090.

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The purpose of this work was to investigate the effects of pre-load static load and dynamic load on the visco-elastic in polycarbonate. In the paper, static-dynamic sweep experiment of polycarbonate was performed on EPLEXOR 500N, which was manufactured by GABO of Germany. The variation laws of storage modulus, loss modulus and loss tangent as changing dynamic load in a large range were systematically analyzed and the spectral characteristics of dynamic-viscoelastic under static-dynamic loads were obtained. The experiment results on dynamic visco-elastic under the high load shows that the load effects on dynamic visco-elasticity of polycarbonate performing on the changing of the dynamic visco-elastic parameters, storage modulus become lager with the increasing of static load and decreasing with the increasing of dynamic load, while loss tangent decreases with the increasing of dynamic load and varies in a more complicated pattern as the increasing of static load.

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Sone, Hiroki, and Mark D. Zoback. "Mechanical properties of shale-gas reservoir rocks — Part 1: Static and dynamic elastic properties and anisotropy." GEOPHYSICS 78, no. 5 (September 1, 2013): D381—D392. http://dx.doi.org/10.1190/geo2013-0050.1.

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Understanding the controls on the elastic properties of reservoir rocks is crucial for exploration and successful production from hydrocarbon reservoirs. We studied the static and dynamic elastic properties of shale gas reservoir rocks from Barnett, Haynesville, Eagle Ford, and Fort St. John shales through laboratory experiments. The elastic properties of these rocks vary significantly between reservoirs (and within a reservoir) due to the wide variety of material composition and microstructures exhibited by these organic-rich shales. The static (Young’s modulus) and dynamic (P- and S-wave moduli) elastic parameters generally decrease monotonically with the clay plus kerogen content. The variation of the elastic moduli can be explained in terms of the Voigt and Reuss limits predicted by end-member components. However, the elastic properties of the shales are strongly anisotropic and the degree of anisotropy was found to correlate with the amount of clay and organic content as well as the shale fabric. We also found that the first-loading static modulus was, on average, approximately 20% lower than the unloading/reloading static modulus. Because the unloading/reloading static modulus compares quite well to the dynamic modulus in the rocks studied, comparing static and dynamic moduli can vary considerably depending on which static modulus is used.

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Lu, Ping, Xin Mao Li, Xue Qiang Ma, and Wei Bo Huang. "Studies the Properties of Polyaspartic Polyurea Coated Concrete under Coaction of Salt Fog and Freeze-Thaw." Advanced Materials Research 455-456 (January 2012): 781–85. http://dx.doi.org/10.4028/www.scientific.net/amr.455-456.781.

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. This paper mainly studied the properties of PAE polyurea coated concrete under coactions of salt fog and freeze-thaw. After exposed salt fog conditions for 200d, T3, B2, F2 and TM four coated concrete relative dynamic elastic modulus have small changes, but different coated concrete variation amplitude is different. T3 coated concrete after 100 times of freeze-thaw cycle the relative dynamic elastic modulus began to drop, 200 times freeze-thaw cycle ends, relative dynamic elastic modulus variation is the largest, decrease rate is 95%, TM concrete during 200 times freeze-thaw cycle, relative dynamic elastic modulus almost no change, B2 concrete and F2 concrete the extent of change between coating T3 and TM. After 300 times the freeze-thaw cycle coated concrete didn't appear freeze-thaw damage phenomenon. Four kinds of coating concrete relative dynamic elastic modulus variation by large to small order: T3 coated concrete > B2 coated concrete >F2 coated concrete > TM coated concrete, concrete with the same 200d rule. Frost resistance order, by contrast, TM coated concrete > B2 coated concrete > F2 coated concrete > T3 coated concrete.

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Geng, Min, Debin Wang, and Peiyong Li. "Undrained Dynamic Behavior of Reinforced Subgrade under Long-Term Cyclic Loading." Advances in Materials Science and Engineering 2018 (October 23, 2018): 1–9. http://dx.doi.org/10.1155/2018/5685789.

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To study the dynamic behavior of reinforced subgrade, a series of undrained cyclic triaxial tests of reinforced soil (the specimen a height of 50 cm and a diameter of 20 cm) were performed in this paper. The specimens were tested by varying confining pressure, vibration frequency, dynamic stress amplitudes, and reinforced layers. Orthogonal experiment is a better way to optimize the process of experiment. Impact on dynamic behavior of the reinforced soil specimens is discussed through orthogonal design of experiments in four factors and three levels. This study has demonstrated that the order of dynamic elastic modulus of reinforced soil is influenced by dynamic stress amplitude, frequency, reinforced layer, and confining pressure within changing in factor level. The dynamic stress amplitude has great influence on the dynamic elastic modulus of reinforced soil. The bearing capacity and dynamic elastic modulus of reinforced subgrade decrease slightly with the increase of dynamic strain. Frequency has an influence on the dynamic elastic modulus. It is shown that the cumulative strain of reinforced soil is related to the vibration frequency. The test results also exemplify the reinforced subgrade restrict lateral displacement of subgrade and reduce settlement of subgrade under long-term cyclic loading.

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Sitharam, T. G., M. Ramulu, and V. B. Maji. "Static and Dynamic Elastic Modulus of Jointed Rock Mass." International Journal of Geotechnical Earthquake Engineering 1, no. 2 (July 2010): 89–112. http://dx.doi.org/10.4018/jgee.2010070107.

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In this paper the compressive strength/elastic modulus of the jointed rock mass was estimated as a function of intact rock strength/modulus and joint factor. The joint factor reflects the combined effect of joint frequency, joint inclination and joint strength. Therefore, having known the intact rock properties and the joint factor, jointed rock properties can be estimated. The test results indicated that the rock mass strength decreases with an increase in the joint frequency and a sharp transition was observed from brittle to ductile behaviour with an increase in the number of joints. It was also found that the rocks with planar anisotropy exhibit the highest strength in the direction perpendicular to the anisotropy and the lowest at an inclination of 30o-45o in jointed samples. The anisotropy of the specimen influences the dynamic elastic modulus more than the static elastic modulus. The results were also compared well with the published works of different authors for different type of rocks.

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Huo, Jun Fang, Jian Jun Chu, and Hui Yang. "Experimental Study on Frost Resistance Properties of Pumice Mixed Aggregate Concrete." Advanced Materials Research 476-478 (February 2012): 1661–64. http://dx.doi.org/10.4028/www.scientific.net/amr.476-478.1661.

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Different amount of pumice were used to replace gravel to make mixed aggregate concrete, the fast freeze-thaw cycle test were conducted and the influence of pumice rate substitution to the frost resistance properties of concrete were studied.The mass loss rate, strength loss and relative dynamic elastic modulus were regarded as the evaluation index of frost resistance properties of concrete. Results showed that the mass loss rate and strength loss rate gradually decreased and the relative dynamic elastic modulus gradually increased with the increase of pumice rate, the mass loss rate, strength loss rate and the relative dynamic elastic modulus gradually decreased with the increase of freeze-thaw cycles. Polypropylene fibers could reduce the strength loss rate, improved the relative dynamic elastic modulus, but had little effect to improve the mass loss. Through the frost resistance, the frost resistance of concrete improved with the increase of pumice content, at the same time, polypropylene fiber also could improve the frost resistance of concrete.

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Yin, Zhi Gang, Jun Feng, Shu You Huang, and Bing Fang Zhao. "Experimental Study of Frost-Resistance Properties of Silica Fume Concrete." Applied Mechanics and Materials 584-586 (July 2014): 1626–29. http://dx.doi.org/10.4028/www.scientific.net/amm.584-586.1626.

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The frost resistance of low strength concrete is researched. In order to evaluate the effect of different content of silica fume on frost resistance，the quality of the cement 6%, 9%, 12% silica fume are respectively added into concrete. Freezing-thawing test results show that: the silica fume concrete has good frost resistance. Content of silica fume on concrete is not almost effect to quality loss rate. In 0-250 times of freezing-thawing cycle range, it is smaller that relative dynamic elastic modulus change rate. Relative dynamic elastic modulus of ordinary concrete decreases rapidly after 250 times of freezing-thawing cycle while dynamic elastic modulus decrease rate of the silica fume concrete tends to slow. The freezing -thawing cycles up to 350 times, silica fume concrete relative dynamic elastic modulus is 1.5 times that of ordinary concrete that show the silica fume concrete frost resistance is better than that of ordinary concrete.

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Gong, Fei, Bangrang Di, Jianxin Wei, Pinbo Ding, He Tian, and Jianqiang Han. "A study of the anisotropic static and dynamic elastic properties of transversely isotropic rocks." GEOPHYSICS 84, no. 6 (November 1, 2019): C281—C293. http://dx.doi.org/10.1190/geo2018-0590.1.

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The elastic properties of rock are major factors affecting hydraulic fracturing. Static elastic properties can be estimated using geomechanical laboratory tests, whereas dynamic properties can be estimated from elastic-wave velocity and rock density. We prepared two synthetic shales containing different clay minerals and one natural shale and focused on the elastic properties for the full tensor of elasticity and their anisotropy. The static and dynamic properties of these dry samples were obtained based on triaxial tests during loading and unloading. The results suggest that the synthetic and natural shale indicate high similarity in the static and dynamic properties. The dynamic Young’s modulus and Poisson’s ratio increase with increasing axial stress during loading and unloading. For the static properties, the static Poisson’s ratio increases with axial stress during loading and unloading. However, differences exist between the static and dynamic Young’s moduli during loading, with the static Young’s modulus decreases with the increasing axial stress at a high stress level. In addition, the static Young’s modulus is consistently lower than the dynamic Young’s modulus during loading and unloading, but the static Poisson’s ratio is larger or smaller than the dynamic Poisson’s ratio. During loading and unloading, there could be approximately a 30% difference when estimating static elastic properties from the static-dynamic relations, depending on which static moduli are used. Furthermore, the static and dynamic properties of the samples are strongly anisotropic, and the anisotropy of elastic properties is sensitive to the axial stress and the clay minerals.

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Su, Xiao Ping, and Hao Yue Sun. "Evaluating the Air-Entraining Concrete Performance Decay Rule under Long-Term Salts Corrosion Using MATLAB Software." Advanced Materials Research 1015 (August 2014): 124–28. http://dx.doi.org/10.4028/www.scientific.net/amr.1015.124.

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In the concrete salt-soaking durability test, the dynamic elastic modulus of concrete is more sensitive to the concrete damage than the mass, and can reflect the concrete durability better. In this paper,the relative dynamic elastic modulus of concrete is used as the evaluation index of concrete durability. Its attenuation law is made the multiple linear regression by using MATLAB software. The evaluation model and its applicable conditions of the relative dynamic elastic modulus of air-entraining concrete under the action of the long-term salt immersion are obtained, which can be used to evaluate and precast the durable degree of air-entraining concrete in the salt environment.

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Liu, Jing Sen, Hai Bo Li, Guo Kai Zhang, and Jian Deng. "Correlations among Physical and Mechanical Parameters of Rocks." Applied Mechanics and Materials 865 (June 2017): 366–72. http://dx.doi.org/10.4028/www.scientific.net/amm.865.366.

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In order to improve the accuracy of the rock mechanical parameters, the correlations among physical and mechanical parameters were investigated. A large number of laboratory testing results curried out on 408 rock specimens including metamorphic rocks, sedimentary rocks and igneous rocks. Through the statistical analysis of the laboratory test data, several regression equations among rock material parameters were established. The research suggests that, in addition to Poisson's ratio, the mechanical parameters (unconfined compressive strength (UCS), elastic Young’s modulus, shear modulus) relate well to physical parameters (porosity, P-wave velocity), and the relationships are mainly described by power and exponential correlations which have good squared regression coefficients. The correlation between elastic Young’s modulus and dynamic elastic modulus was established, as well as the relationship between shear modulus and dynamic shear modulus.

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Sato, Masatoshi, Minoru Ueda, Norio Hasebe, and Hidetaka Umehara. "Dynamic Elastic Modulus of Dam Concrete under Earthquake Motion." Doboku Gakkai Ronbunshu, no. 564 (1997): 43–55. http://dx.doi.org/10.2208/jscej.1997.564_43.

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HORIUCHI, HISAYA. "DYNAMIC PROPERTIES OF ELASTIC MODULUS IN SOME HETEROGENEOUS GELS." Journal of Texture Studies 21, no. 2 (July 1990): 141–54. http://dx.doi.org/10.1111/j.1745-4603.1990.tb00471.x.

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Yuan, Jian Yi, Tao Cheng, Ding Bang Zhang, Zhen Hua Wu, and Jian Xiang. "Research on Relationship of Dynamic Calculation Parameters and Deformation." Applied Mechanics and Materials 178-181 (May 2012): 1459–62. http://dx.doi.org/10.4028/www.scientific.net/amm.178-181.1459.

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In order to analyze the effect of dynamic calculation parameters to subgrade deformation, cross-section in the Shanghai-Nanjing high-speed railway is chosen and the numerical simulation calculation method is applied. Through numerical calculation of 121 kinds of conditions combining dynamic shear modulus and dynamic damping ratio, the dynamic elastic deformation of point A and dynamic partial stress of bottom layer of foundation bed were studied. It shows that the maximum dynamic elastic deformation of point A reduces with dynamic shear modulus and dynamic damping ratio increasing. Moreover, the value of average dynamic partial stress augments with dynamic shear modulus increasing, and reduces along with the increase of dynamic damping ratio. Using nonlinear fitting method of constructing three polynomial surface equations, the function of total deformation with dynamic calculation parameters is obtained.

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Li, Ting-Ting, Jiunn Fang, Chen-Hung Huang, Ching-Wen Lou, Jan-Yi Lin, Mei-Chen Lin, Yueh-Sheng Chen, and Jia-Horng Lin. "Numerical simulation of dynamic puncture behaviors of woven fabrics based on the Finite Element Method." Textile Research Journal 87, no. 11 (September 2, 2016): 1308–17. http://dx.doi.org/10.1177/0040517516652343.

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Research on the simulation and modeling of dynamic puncture penetration is more complex problem due to full consideration of the tightness of the fabric and the sharp profile of the puncture. This study presents numerical simulation of complicated dynamic puncture behaviors on the basis of the roles of extension and stress-wave transmission on the deformation. The unit cell model was used to simulate the yarn crimp and extension during the uniaxial dynamic puncture process. In addition, the puncture deformation and stress distribution of woven fabrics with different elastic modulus and friction distance were simulated followed with dynamic puncture penetration. The result shows that dynamic puncture damage critically depends on the elastic modulus of yarns and the distance between yarns; the inter-yarn distance affects dynamic puncture resistance more significantly. Dynamic puncture stress nonlinearly increases with the elastic modulus, and linearly decreases with yarn distance. The research result indicates that weaving density can be increased to improve dynamic puncture resistance more obviously.

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Yin, Shui Ping, and Min Yu. "Visco-Elastic Study on Filled Polymer Composites." Advanced Materials Research 239-242 (May 2011): 2038–41. http://dx.doi.org/10.4028/www.scientific.net/amr.239-242.2038.

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Dynamic mechanical behavior of materials, which is the response under cyclic stress(cyclic strain/force) in vibration condition, is different from its static behavior. The latter is the behavior of material in a monotonic increasing stress(strain/force). Dynamic mechanics analysis (DMA) is a method to measure the dynamic stiffness and damping in a lower stress level(linear elastic and lower than its yield strength). In the paper, dynamic mechanical experiments of filled polymer materials, polysulfone(PSU) and polyurethane(PUR), were performed on EPLEXOR 500N which manufacturing by GABO of Germany, the relationship of storage modulus E', loss modulus E" and loss tangent to pre-static load and frequency were systemically analyzed.

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YANG, FUQIAN. "EFFECT OF VISCOUS LIQUID FILM ON DYNAMIC CONTACT IN ATOMIC FORCE MICROSCOPY." Biophysical Reviews and Letters 01, no. 01 (January 2006): 97–106. http://dx.doi.org/10.1142/s1793048006000033.

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This letter incorporates squeezing flow with the Hertz contact theory in analyzing the dynamic behavior of an AFM tip in contact with an elastic substrate and a liquid film. To the first order of approximation, a new dynamic equation describing the motion of the AFM tip is presented, from which closed-form solutions of the stored contact modulus and loss contact modulus are obtained. The results show that the stored contact modulus depends on the frequency of the oscillation, the elastic properties of the elastic material and the mass of the tip, while it is independent of the viscosity of the liquid film. These provide a theoretical basis for the characterization of the elastic properties of biological materials and nanostructures by using the technique of continuous stiffness measurement.

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Zeng, Zhi Ping, Xue Song Wang, Wen Rong Chen, and Guang Cheng Long. "Influence Analysis of Mortar Elastic Modulus to CRTS III Slab Track Vertical Dynamic Response." Applied Mechanics and Materials 166-169 (May 2012): 314–17. http://dx.doi.org/10.4028/www.scientific.net/amm.166-169.314.

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A train-CRTS Ⅲ slab track coupling dynamic model was proposed to study the dynamic performance of the system. Rail was modeled as space beam element. Both slab and HGT layer were modeled as plate element respectively. The vertical and lateral connections between rail, slab, HGT layer, and subgrade were modeled as spring-damper element. The vibration matrix equation of the system was established on the basis of the principle of the total potential energy with stationary value in elastic system dynamics and the rule of “set-in-right-position” for formulating system matrices. The influence of mortar elastic modulus to CRTS Ⅲ slab track vertical dynamic response was calculated when the train runs at 350 km/h. The results show that the larger of mortar elastic modulus, the faster the vibration between rail and slab decays, and the slower the vibration between slab and HGT layer decays.

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Zhang, Hua, Fei Li, and Yu Wei Gao. "Study on the Dynamic Performance of Asphalt Concrete under Passive Confined Pressure." Applied Mechanics and Materials 226-228 (November 2012): 1755–59. http://dx.doi.org/10.4028/www.scientific.net/amm.226-228.1755.

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An improved passive confining pressure SHPB method was used to study the dynamic mechanical behaviors of asphalt concrete under quasi-one dimensional strain state. The effect of confining jacket material and its geometrical sizes on the confining pressure were discussed. The dynamic strength, dynamic modulus of elasticity and dynamic Poisson ratio of asphalt concrete were obtained. The influential rules of confining pressure on the dynamic properties were studied by comparing the stress-strain curves of asphalt concrete under different stress states. The study found that passive confining greater impact on the strength of asphalt concrete than elastic modulus and Poisson ratio, but the elastic modulus improved with the increase of confining pressure.

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Cui, Ling Zhi, Gao Min Li, Yi Ting He, Qin Liao, and Fei Luo. "Status Analysis of the Frozen Soil’s Dynamics Parameter Study." Advanced Materials Research 941-944 (June 2014): 2626–30. http://dx.doi.org/10.4028/www.scientific.net/amr.941-944.2626.

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In this paper, the author points out several key problems needed to be solved about the dynamics of frozen soil by reviewing related literatures about hysteretic curve of frozen soil ,dynamic constitutive relation and dynamical parameter. The problems are the insufficient understanding on morphological characteristics of hysteretic curve and how to transform qualitative understanding into quantitative understanding about morphological characteristics of hysteretic curve. The problem is the rationality of selecting the dynamic constitutive model, namely how to establish the engineering applicable model which conforms to the actual soil mechanics performance.The problem is the rationality of the calculation method about dynamic elastic modulus and damping ratio, namely how to define dynamic modulus of elasticity of frozen soil correctly and the limitation of using the classical method to calculate the damping.

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Kurakina, Elena, Sergej Evtyukov, and Jaroslav Rajczyk. "Diagnostic assessment of an impact of static and dynamic vehicle loads on covering of roadway." MATEC Web of Conferences 334 (2021): 01014. http://dx.doi.org/10.1051/matecconf/202133401014.

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The article presents diagnostic possibilities for testing covering of roadway through dynamic and static loading units. The article presents features, advantages and principal characteristics of the equipment: die unit, Dina-3M, UDN-NK, Dynatest unit. The main parameters of the dynamic impact units. The article also presents results of tests by dynamic and static loading, defines «flexural bowls», elastic module and the coefficients of reduction of the elastic modulus to the static modulus.

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Huang, Chun Ying, Man Hua Wan, and Xiao Jun Wang. "FeSiB Annealing Technology Based on Amorphous Ribbons of the Linear Expansion Coefficient." Key Engineering Materials 428-429 (January 2010): 537–39. http://dx.doi.org/10.4028/www.scientific.net/kem.428-429.537.

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The 4.5mm wide 25μm thick Fe78Si9B13 amorphous alloys were prepared by single-roller method, and it was annealed. The elastic modulus, tensile deformation and line expansion coefficient were investigated by Q800 (dynamic mechanical thermal analyses, DMA). The results showed that the elastic modulus, tensile deformation and line expansion coefficient were enhanced when annealed. Comparing with the annealed ribbons, the change rules of elastic modulus, tensile deformation and line expansion coefficient of the quenched are evident, that the elastic modulus decreases and tensile deformation increase with temperature increases, but line expansion coefficient firstly increase then decrease with temperature increases.

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Pereira, Inês. "Overview on Determination of Elastic and Damping Properties of Different Materials using Impulse Excitation Technique." U.Porto Journal of Engineering 3, no. 3 (March 27, 2018): 35–41. http://dx.doi.org/10.24840/2183-6493_003.003_0004.

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Knowledge of elastic and damping properties of materials is very relevant for the analysis and design of components, as they are relevant parameters in the performance of structural materials. The impulse excitation technique is a renowned dynamic technique for measuring dynamic elastic properties as Young´s modulus, shear modulus and Poisson’s ratio, as well as damping properties. This paper provides a review on the applicability of the impulse excitation technique in the analysis of elastic and damping properties of different types of materials.

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Rudnitsky, V. A., A. P. Kren, and G. A. Lantsman. "EVALUATION OF METALLIC MATERIALS PLASTICITY BY DYNAMIC INDENTATION METHOD." Litiyo i Metallurgiya (FOUNDRY PRODUCTION AND METALLURGY), no. 2 (July 4, 2017): 81–87. http://dx.doi.org/10.21122/1683-6065-2017-2-81-87.

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The method of plasticity test of metallic materials realized by means of a dynamic dimpling of material by a spherical tip is offered. The measured value of plasticity is defined by a ratio of plastic and complete deformations in the formed indentation which considers influence of an elastic modulus of material. The dependence connecting plasticity and dynamic hardness of materials is received. Experiments on metals from 70 to 380 GPA having an elastic modulus and hardness up to 62 HRC are made.

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Li, Ning, Sisi Zhang, Guangcheng Long, Zuquan Jin, Yong Yu, Xiaoying Zhang, Chuansheng Xiong, and He Li. "Dynamic Characteristics of Lightweight Aggregate Self-Compacting Concrete by Impact Resonance Method." Advances in Civil Engineering 2021 (March 26, 2021): 1–11. http://dx.doi.org/10.1155/2021/8811303.

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Understanding the dynamic behavior of Lightweight Aggregate Self-Compacting Concrete (LWASCC) is of importance to the safety of concrete structures serving in dynamic loading conditions. In this study, the fundamental dynamic properties of LWASCC with three types of LWA were investigated by the impact resonance method. Results show that the dynamic elastic and shear modulus generally decrease with the increase of LWA volume fraction, whereas three types of LWA exert limited influence on dynamic Poisson’s ratio. The dynamic elastic and shear modulus show good linear dependence upon compressive strength. The inclusion of three types of LWA significantly increases the damping ratio, indicating significantly enhanced damping capacity of LWASCC under dynamic loading conditions. The damping ratio of LWASCC is improved by 2.0%, 4.4%, and 2.9% when adding 1% (by volume) expanded clay, rubber, and expanded polystyrene, respectively. The compressive strength and dynamic performances of LWASCC are highly influenced by the intrinsic properties (elastic modulus, damping capacity, wettability, etc.) and geometrical characteristics (size, surface roughness, etc.) of LWA, as well as the LWA-matrix bonding capacity.

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Panesar, D. K., and S. E. Chidiac. "Ultrasonic pulse velocity for determining the early age properties of dry-cast concrete containing ground granulated blast-furnace slag." Canadian Journal of Civil Engineering 34, no. 5 (May 1, 2007): 682–85. http://dx.doi.org/10.1139/l07-039.

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This study evaluates the potential use of ultrasonic pulse velocity (UPV) for determining the early age compressive strength of dry-cast concrete containing varying percentages of ground granulated blast-furnace slag (GGBFS). The proposed approach includes computing the dynamic elastic modulus from UPV measurements, evaluating the static elastic modulus from experimentally measured dynamic-to-static elastic modulus ratios, and determining the compressive strength from the static elastic modulus using formulae suggested in ACI-363. The early age strengths of dry-cast concrete containing varying amount of GGBFS, which are determined using UPV measurements, are in good agreement with the measured strength. The evaluation is also extended to include five datasets reported in published literature for concrete containing varying types and amounts of mineral admixtures. Key words: concrete, compressive strength, dry cast, early age properties, ground granulated blast-furnace slag (GGBFS), ultrasonic pulse velocity (UPV).

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Lee, Byung Jae, Seong-Hoon Kee, Taekeun Oh, and Yun-Yong Kim. "Evaluating the Dynamic Elastic Modulus of Concrete Using Shear-Wave Velocity Measurements." Advances in Materials Science and Engineering 2017 (2017): 1–13. http://dx.doi.org/10.1155/2017/1651753.

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The objectives of this study are to investigate the relationship between static and dynamic elastic moduli determined using shear-wave velocity measurements and to demonstrate the practical potential of the shear-wave velocity method for in situ dynamic modulus evaluation. Three hundred 150 by 300 mm concrete cylinders were prepared from three different mixtures with target compressive strengths of 30, 35, and 40 MPa. Static and dynamic tests were performed at 4, 7, 14, and 28 days to evaluate the compressive strength and the static and dynamic moduli of the cylinders. The results obtained from the shear-wave velocity measurements were compared with dynamic moduli obtained from standard test methods (P-wave velocity measurements according to ASTM C597/C597M-16 and fundamental longitudinal and transverse resonance tests according to ASTM C215-14). The shear-wave velocity measured from cylinders showed excellent repeatability with a coefficient of variation (COV) less than 1%, which is as good as that of the standard test methods. The relationship between the dynamic elastic modulus based on shear-wave velocity and the chord elastic modulus according to ASTM C469/C469M was established. Furthermore, the best-fit line for the shear-wave velocity was also demonstrated to be effective for estimating compressive strength using an empirical relationship between compressive strength and static elastic modulus.

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ZHOU, YUN, and WEI-JIAN YI. "PHYSICAL PARAMETER IDENTIFICATION OF AN RC FRAME STRUCTURE ON ELASTIC FOUNDATION." International Journal of Structural Stability and Dynamics 09, no. 04 (December 2009): 627–48. http://dx.doi.org/10.1142/s0219455409003211.

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In this paper, the simple genetic algorithm (SGA) is improved by combining with the simulated annealing algorithm (SAA) for the parameter identification of a reinforced concrete (RC) frame on elastic foundation. SGA adopts parallel search strategy, which is based on the concept of "survival of the fittest" in optimization while SAA adopts a serial form and the process is endowed with time-variety probable jumping property so that local optimization could be prevented. The global searching ability is developed by combining the two methods and the new algorithm is named genetic annealing hybrid algorithm (GAHA). Modal experiments were carried out on a four-storey RC frame structural model with isolated embedded footings in laboratory. The measured natural frequencies and mode shapes have been utilized to identify the physical parameters of the frame by the proposed method. Four cases of concrete elastic modulus and foundation dynamic shear modulus are identified, and the results are compared with the usual sensitivity methods (SM). By model updating, the results show that the elastic modulus of concrete increases with respect to the storey. The identified elastic modulus of the concrete is generally larger than that found by compressive testing because the dynamic modulus of concrete is larger than the static modulus of concrete. The identified soil dynamic shear modulus also increases with the storey since the soil property depends on the pressure exerted on the soil. It is also shown that the identified results by GAHA are better than that of SM.

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Ma, Qinyong, Qingqing Su, and Pu Yuan. "Dynamic Behavior and Energy Evolution Characteristic of Deep Roadway Sandstone Containing Weakly Filled Joint at Various Angles." Advances in Civil Engineering 2020 (August 24, 2020): 1–12. http://dx.doi.org/10.1155/2020/8817107.

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Dynamic impact tests were carried out by implying split-Hopkinson pressure bar (SHPB) apparatus under three-dimensional stress state to investigate the influences of weakly filled joint at seven kinds of angles on dynamic behavior and energy evolution characteristic of deep roadway sandstone (985 m below the surface). The results indicated that rebound strain phenomenon was obvious and the growth rate of stress was in two kinds of phased variations. Dynamic peak strain was inversely proportional to joint angle under three different strain rates. Dynamic compressive strength, elastic deformation modulus, and plastic deformation modulus were in similar variable tendencies with incremental joint angles, showing firstly decrease to minimum value at joint angle of 45° and then increase to maximum value at joint angle of 90°. Moreover, the sensitivity of plastic deformation modulus to joint angle was obviously inferior to that of elastic deformation modulus when joint angle increased from 0° to 45°. Furthermore, both elastic deformation modulus and plastic deformation modulus were independent of strain rate, which was contrary to dynamic compressive strength and dynamic peak strain. Additionally, absorption energy release rate was introduced and defined to describe energy release and conversion characteristics of joint specimens. The changed trend of energy reflection coefficient was completely opposite to that of energy transmission coefficient and absorbed energy release rate. Absorbed energy density was linearly decreased with incremental joint angle and was increased with the increase of strain rate.

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Zhao, Dong, Jian Zhong Zhang, and Jian Zhao. "Virtual Instrument for Measuring Elastic Modulus of Wood Floor." Applied Mechanics and Materials 37-38 (November 2010): 1634–37. http://dx.doi.org/10.4028/www.scientific.net/amm.37-38.1634.

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Elastic modulus is one of the most important performance parameters of wood-based material, and plays an important role for predicting and evaluating quality of wood-based material. At present, the traditional problems for measuring elastic modulus of wood-based material are: expensive testing instrument, short precision, low immunity to noise and less ease to connect. This paper presents a new elastic modulus-measuring system based on virtual instrument. The system ensures the following functions: (1) real-time data acquisition, (2) signal processing and analyze, (3) saving the file in the appropriate format, (4) computing dynamic elastic modulus by the natural frequency. The analytical results of our experiments show that it is feasible, reliable and effective to use the proposed instrumentation for measuring elastic modulus of wood-based floor.

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Zhang, Zhu, Ying, and Luo. "Experimental Investigation on the Dynamic Modulus Properties of Methane Hydrate Sediment Samples." Energies 12, no. 22 (November 9, 2019): 4277. http://dx.doi.org/10.3390/en12224277.

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Studying the strength and deformation properties of sediments containing gas hydrates is one of the key problems during the process of hydrate resource exploitation. In this paper, considering the effects of temperatures (−5, −3, −1 °C), confining pressures (0.5, 1, 2 MPa) and porosities (40%, 80%) on the dynamic modulus characteristics of sediments containing methane hydrates, several dynamic loading experiments were conducted. The results show that the sediment structure was more easily destroyed under a larger amplitude of dynamic loading. According to the dynamic stress–strain curves, the skeleton curves of the sediment samples were obtained, and it was shown that the deformation behaved with elastic characteristics in the initial stage, and then plastic deformation increased gradually and played a leading role with the increase in external loading. The maximum dynamic elastic modulus of sediments was reduced under the conditions of higher temperature and porosity, and effectively enhanced under higher confining pressure. Finally, on the basis of the Hardin–Drnevich equivalent model, and considering the influences of temperatures and confining pressures on model parameters, a viscoelastic constitutive model applied to analyze the dynamic modulus characteristics of sediments containing methane hydrate was established. The comparison showed that these calculated values of sediments’ dynamic elastic modulus accorded quite well with the experimental values.

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Naranjo, S. Solórzano, R. Moya, and S. Chauhan. "Early genetic evaluation of morphology and some wood properties of Tectona grandis L. clones." Silvae Genetica 61, no. 1-6 (December 1, 2012): 58–65. http://dx.doi.org/10.1515/sg-2012-0008.

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Abstract An early genetic evaluation of morphology and wood properties of Tectona grandis L. (teak) used two 4-yr-old trials with 36 clones x 3 blocks x 1 ramet (216 trees). Morphologic traits (breast height (DBH), heartwood (HWP), tree height) and some easily measured wood properties (specify gravity, tangential, radial and volumetric shrinkage; growth strain, and dynamic elastic modulus measured in standing tree, in logs, in green lumber and in dried lumber) were evaluated to establish clonal variations and their heritabilities. The broadsense heritability (Ĥ2 is greater than 0.3 for DBH, radial and volume shrinkage, growth strain and dynamic elastic modulus of standing trees and logs. DBH and tree height were not genetically correlated with any wood properties, although DBH was genetically correlated with tree height and the dynamic elastic modulus in dried-lumber. According with above results, the evaluation of heritability and genetic control of wood properties is limited when it is evaluated in the juvenile stage of T. grandis clones. However morphology (DBH and tree height), and two wood properties (radial and tangential shrinkage) and the dynamic elastic modulus of dried-lumber present opportunities in the heritability or genetic control values in juvenile and they can be introduced in the genetic program.

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Dao, Dong Van, Ngoc-Lan Nguyen, Hai-Bang Ly, Binh Thai Pham, and Tien-Thinh Le. "Cost-Effective Approaches Based on Machine Learning to Predict Dynamic Modulus of Warm Mix Asphalt with High Reclaimed Asphalt Pavement." Materials 13, no. 15 (July 23, 2020): 3272. http://dx.doi.org/10.3390/ma13153272.

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Warm mix asphalt (WMA) technology, taking advantage of reclaimed asphalt pavements, has gained increasing attention from the scientific community. The determination of technical specifications of such a type of asphalt concrete is crucial for pavement design, in which the asphalt concrete dynamic modulus (E*) of elasticity is amongst the most critical parameters. However, the latter could only be determined by complicated, costly, and time-consuming experiments. This paper presents an alternative cost-effective approach to determine the dynamic elastic modulus (E*) of WMA based on various machine learning-based algorithms, namely the artificial neural network (ANN), support vector machine (SVM), Gaussian process regression (GPR), and ensemble boosted trees (Boosted). For this, a total of 300 samples were fabricated by warm mix asphalt technology. The mixtures were prepared with 0%, 20%, 30%, 40%, and 50% content of reclaimed asphalt pavement (RAP) and modified bitumen binder using Sasobit and Zycotherm additives. The dynamic elastic modulus tests were conducted by varying the temperature from 10 °C to 50 °C at different frequencies from 0.1 Hz to 25 Hz. Various common quantitative indications, such as root mean square error (RMSE), mean absolute error (MAE), and correlation coefficient (R) were used to validate and compare the prediction capability of different models. The results showed that machine learning models could accurately predict the dynamic elastic modulus of WMA using up to 50% RAP and fabricated by warm mix asphalt technology. Out of these models, the Boosted algorithm (R = 0.9956) was found as the best predictor compared with those obtained by ANN-LMN (R = 0.9954), SVM (R = 0.9654), and GPR (R= 0.9865). Thus, it could be concluded that Boosted is a promising cost-effective tool for the prediction of the dynamic elastic modulus (E*) of WMA. This study might help in reducing the cost of laboratory experiments for the determination of the dynamic modulus (E*).

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Duvaizem, José Hélio, N. M. F. Mendes, J. C. S. Casini, A. H. Bressiani, and H. Takiishi. "Effect of Heat Treatment on Microstructure and Mechanical Properties of Ti-13Nb-13Zr Alloy Produced by Powder Metallurgy." Materials Science Forum 802 (December 2014): 457–61. http://dx.doi.org/10.4028/www.scientific.net/msf.802.457.

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Ti-13Nb-13Zr alloy produced via powder metallurgy was submitted to heat treatment under various conditions and the effects on microstructure and elastic modulus were investigated. Heat treatment was performed using temperatures above and below α/β transus combined with different cooling rates – furnace cooling and water quenching. Microstructure and phases were analyzed employing scanning electron microscopy and X-ray diffraction. Elastic Modulus was determined using a dynamic mechanical analyzer (DMA). The results indicated that α phase precipitation and elastic modulus values increased after heat treatment performed using temperature below α/β transus. However, when it was performed above α/β transus and using higher cooling rate, a decrease in elastic modulus was observed despite higher α phase precipitation, indicating that the microstructural modifications observed via SEM, due to the presence of martensitic α phase, influenced on elastic modulus values.

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Xiao, Jiang, Da Gen Sun, and Li Yan Huang. "Design of Ultrasonic Wave Velocity System for Intensity of Laminated Veneer Lumber Based on AVR Microcontroller." Advanced Materials Research 433-440 (January 2012): 5703–8. http://dx.doi.org/10.4028/www.scientific.net/amr.433-440.5703.

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This paper does research in the independent development detection system for intensity of laminated veneer lumber via ultrasonic wave. By measuring the velocity of ultrasonic wave and other parameters on-line, the dynamic elastic modulus of laminated veneer lumber can be calculated through AVR as the data processing core of this system. And because of the dynamic elastic modulus showed positive correlation in plank strength, the timber grade can be divided through this system.

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Cai, Xiaopei, Yanglong Zhong, Xiaocheng Hao, Yanrong Zhang, and Rixin Cui. "Dynamic behavior of a polyurethane foam solidified ballasted track in a heavy haul railway tunnel." Advances in Structural Engineering 22, no. 3 (October 2, 2018): 751–64. http://dx.doi.org/10.1177/1369433218799154.

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Dynamic behavior of a new type of track using the polyurethane foam solidified ballast in heavy haul railway tunnels is comprehensively investigated in this study. First, a dynamic model of the vehicle–track–tunnel interaction system was developed based on the multi-body system dynamics theory and finite element method. Then, the dynamic effects of the polyurethane foam solidified ballast track on the train and the surrounding infrastructures were calculated and compared to those of the traditional ballasted track. Moreover, the effects of the elastic modulus and the solidified area size of polyurethane foam solidified ballast on the dynamic behavior were analyzed. Results show that, compared to the traditional ballast bed, polyurethane foam solidified ballast decreases the track stiffness and the vibration acceleration of the tunnel, while does not affect the vehicle safety (derailment coefficient and the rate of wheel load reduction). A larger elastic modulus of polyurethane foam solidified ballast has little effects on the wheel–rail interaction and the vibration acceleration of the tunnel, while a smaller modulus results in amplification of the displacements of rails and sleepers. Considering the vehicle–track interaction and tunnel vibration, the optimal elastic modulus of polyurethane foam solidified ballast is suggested to be 60–80 MPa. In addition, smaller solidified area of polyurethane foam solidified ballast presents lower effects on the vibration reduction and rate of wheel load reduction, while larger area leads to a higher derailment coefficient and cost. Therefore, an optimal solidified area size of polyurethane foam solidified ballast with the top width of 0.85 m is recommended.

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Journal articles on the topic 'Dynamic elastic modulus'

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