Journal articles on the topic 'Fastening of cargo'

Fastening of cargo on the car. Calculation of load shift, elongation and forces in elastic elements of fasteners. Describe the parameters of the load and the physical and geometric parameters of the load fastening; give the results of the calculation of the longitudinal forces perceived by the elements of the load fastening. The article uses the basic law of dynamics in relative motion for the non-ideal connection known from theoretical mechanics. The results of the calculation of the longitudinal forces perceived by the load fastening elements, which allowed determining the load shifts along the car, elongation and forces in the flexible fastening elements are presented. Example calculation contributes to the practical application of a new method of calculating the elements of fastening on the car in the development of schemes of placement and fastening of goods of arbitrary geometry. The results of calculations revealed that the accepted value of the coefficient of longitudinal dynamics of the car corresponds to the shunting collision of the car on the hump yard in the marshalling yards.

Cargo securing on a railway platform, elastic and retention fasteners, longitudinal transport force of inertia, forces in elastic fastenings. Purpose: The paper presents the calculation of the longitudinal transport force of inertia; determines the longitudinal force perceived by the elastic elements of the cargo securing; determines the reactions of retention bars depending on the number of bars and fasteners (nail); calculates the sum of all holding forces; calculates the forces in the elastic fasteners when exposed to longitudinal forces. Research methods: To determine the forces in the cargo securing devices, existing calculation methods are used. Moreover, the formulas of these techniques are presented in a form convenient for calculation. Main results: The paper proves that according to the existing method, the force in all elastic cargo fasteners under the influence of longitudinal forces has the same value, regardless of the different arrangement of the geometric parameters of the fasteners in space. The forces in them are more than 1.6 times higher than the permissible values. The calculations of forces in the elastic fasteners, which are performed by the specified method, are given. The results of the comparative analysis showed that the forces in all wire fasteners, in contrast to the existing calculation method, have different values. However, the strength of the second pair of wire fasteners of both one and the other direction is not ensured - the force in them more than two times exceeds the permissible value (61/24.8≈2.5), which will result in their destruction during the cargo transportation. Conclusions and their significance for the industry: Existing calculation methods do not provide guarantee strength of cargo fasteners. In the future, to calculate the fastening of cargo by shippers in the railway industry, a new calculation procedure should be applied for the allocation and fastening of cargo on the car.

Inaccuracy of the existing methodology for calculating cargo fastening. Cargo fastening by flexible and retention elements. The paper should define the “shearing” force across the car as the sum of the transverse transport inertia and wind load, taking into account the safety factor from tipping over; determine the transverse force perceived by the means of securing the load, taking into account the reaction of the retention bars of only one direction; calculate the forces in the elastic fasteners when exposed to shearing forces, taking into account the geometry of the fasteners according to existing methods. The research methods are based on the basic law of dynamics for the relative motion of a material point, where the transverse and vertical transferring inertia forces are formally assigned to external forces. The paper proves that according to the existing methodology, the force in all elastic cargo fasteners under the influence of transverse forces has the same value, regardless of the different arrangement of the geometric parameters of the fasteners in space. This is not true. The calculations of forces in the elastic fastening elements according to Appendix 8 of the existing methodology are given. Under the influence of transverse forces, the strength of the first and second pairs of elastic fasteners, both one and the other direction, are not provided by the method of Appendix 8 - the forces in the fasteners are greater than the permissible one (24.8 kN). Existing calculation methods do not ensure the strength of the cargo fastening elements.

The basic concepts of modern risk and reliability theory are reviewed. Application of these concepts to topics arising in the analysis of ship motions, cargo sea-fastening design and voyage risk studies is explored. The role of risk analysis in decision theory is briefly discussed and the paper concludes with a suggested program of analysis for marine activities and enterprises subject to sea-action induced risk.

AbstractEnsuring transport safety is one of the key areas of transport companies’ operations. Management and organization processes not only in the intermodal transport are associated with decision-making in regard to adequate load securing, which is exposed to the inertia forces resulting from the movement of transport means. Regardless, the responsibility of individual entities in the process and the applicable insurance, the basic aspect to ensure transport safety is the correct securing of the cargo. In the article, the authors present elements of calculation models for different methods of securing cargo. Calculations were performed for the selected type of load on the specific semi-trailer meeting the requirements of the XL Code adapted for intermodal transport. The analysis of safety management in transport in the aspect of decision-making about the method of securing the cargo was also made.

During the transportation of goods, damage and destruction of the transported cargo constitute a very large part of the damage. The most common direct cause of damage is an improper arrangement and securing of the transported load. An improperly secured load may pose a threat to the transporters and bystanders. Incorrectly secured loads can fall from the vehicle, obstruct movement, and cause injury or death. In addition, improperly secured loads can cause injury or death in heavy braking or a collision. The way the load is distributed and secured on the vehicle can negatively affect driving behaviour, making it difficult to control the vehicle. This article presents the conditions related to the transport of loads in road transport, describes both the forces that act on the load during the journey of a vehicle and the most important techniques for securing loads in road transport.

This paper studies multi-vehicle and multi-cargo loading problem under the limited loading capacity. According to the characteristics of model and problem, fast taboo search algorithm is used to get the optimization solution from the overall situation. Firstly, it applies newly improved insertion method to construct initial solution in order to improve the feasibility of the solution. Secondly, it centers cubage-weight balance to design three operations for fastening the speed of convergence, stock elite to improve the searching efficiency of algorithm. Finally, the good performance of this algorithm can be proved by experiment calculation and concrete examples for solving practical problems.

At the site of cargo package binding in cargo spacecraft, the binding belt tension is loaded with a ratchet device. It is determined by experience of operators, therefore it’s difficult to quantify the force and the reliability of the binding belt is low. Based on the dimension analysis method, a semi-quantitative model was established between the binding belt tension and the ratchet force of the fastening device. The motion of the binding process was carefully observed and analyzed based on Analysis of Therbligs. On this basis, the standard packing process is developed, which improves the repeatability of loading and packing pre loading. A loading test platform for cargo loading is built with small tension sensor and tension tester, and a large number of tension data and ratchet force data are obtained. Based on the least-squares linear data fitting, four coupling models for the four binding belts were established. The coupling model verification experiments show that the calculated values are in good agreement with the measured values, and the errors are mostly lower than 5%. The model can be applied to the quantification of the binding belt tension.

This paper dwells upon securing solid cargo on a railcar. Transverse cargo shift and forces of elastic securing devices. The authors sought to calculate the shearing force acting on the elastic securing elements and retention bars; the retentive forces that prevent cargo from shifting across the car (the transverse shift); the transverse cargo shift; the force of elastic securing elements as exposed to transverse forces. This study relies on the second law as applicable to relative motion for a frictional constraint, as known in theoretical mechanics. The paper presents the calculated shearing and retentive forces. The authors calculated the equivalent stiffness of elastic securing elements. They thus computed the transverse shift (displacement) of cargo and the elongation of each elastic element that secures the cargo. They also found the forces of elastic securing elements as exposed to transverse forces. It was thus discovered that the forces of the second securing pair were more than double the acceptable limit, which would cause that pair to break during transport. To make the second elastic pair stronger, one might double the number of retention-bar fasteners so that the forces of the second fastening pair wouldn’t exceed the limits. An example of calculation is useful in developing a new methodology for calculating the elements of cargo securing on a car. The calculation results proved that to ensure guaranteed safety and reliability of the transportation process, it is necessary to either increase the number of securing elements of the retention bar, or increase the number of elastic securing elements with subsequent recalculation of forces in all elastic securing elements.

An important role in the market of transport services belongs to container transportation. Railroads, especially under the conditions of increased competition from road transport, must respond quickly to the needs of the market and the growing demand for container transportation, including interstate traffic. Demand for container transportation can vary significantly during the year, which testifies to the expediency of introducing removable equipment on universal railroad freight cars that are involved in the deliveries of containers. This paper reports the design of a removable frame structure for a universal platform that could carry two 20-ft or one 40-ft container. The proposed technical solution does not require changes in the structure of the car and changes in its model; with a decrease in the demand for container transportation, it would allow this car to be used for its main purpose. According to the current methodology, the efforts that operate on the frame during the transportation of containers have been determined. The strength of the proposed structure was estimated by a finite-element method. The maximum stresses arising in the proposed structure are 164.4 MPa; they occur in the corners of the stops attached to the stand-up staples of the platform. The resulting stress values do not exceed the allowable ones. The results of calculating the removable equipment indicate its sufficient strength. Requirements for placing cargo on the rolling stock assume a mandatory check to fit the dimensions, which confirmed that the container hosted by the frame does fit them. The proposed structure makes it possible to abandon disposable fastening parts, improve the safety of container transportation, and increase competitiveness in the container transportation market.

The main purpose of the article is to consider the simulation of the natural oscillations of the air assault rappelling system “Kanat-1”. The object of consideration is a set of removable onboard equipment for rappelling air assault "Kanat-1" for landing from the cargo hatch of Mi-8 helicopters. Air assault rappelling system is an oscillating system that has certain natural frequencies of oscillation of the item, which depend on the number of paratroopers on the rope and their placement on it. The airframe of the Mi-8 helicopter has its own frequencies within the ranges of 3.1 - 3.3; 8 - 9; 15 - 17 Hz with which, and their divisibles the natural frequencies of the item should not coincide. In real operating conditions, determining the natural frequencies of the elements of the item under load is problematic. A system of dynamic models is built which allows determining the natural frequencies of air assault rappelling system oscillations at arbitrary placement of up to three paratroopers weighing up to 140 kg each, which can be hung simultaneously on one of the ropes in constant motion while moving the points of contact with the rope. In general, at the maximum load on the rope (three paratroopers), the mathematical model represents a system of three second-order differential equations. Eight variants for loading the rope with paratroopers are considered. The obtained oscillation frequencies of the air assault rappelling system do not coincide with the oscillation frequencies of the helicopter airframe which proves the effectivity of the air assault rappelling system. Recommendations for regulation of frequency characteristics of air assault rappelling system by replacement of a fastening element of a rope to a traverse are developed.

Object and purpose of research. This paper describes physical modeling of interaction process of abnormal wave (freak wave) with a marine floating structure in a seakeeping tank of the Krylov State Research Center. Freak wave is extremely dangerous because of the difference from wind waves by an unusually steep front slope and a gentle trough. Freak wave appears suddenly and collapses rapidly. Research of effect process features is necessary for understanding and analysis of the object behavior at extreme sea conditions. As experiment results it was necessary to obtain empirical data of sea object motions and accelerations at interaction with freak wave on different course angles and speeds. The obtained physical experiment results will be the foundation of theoretical studies and numerical calculation methods. Materials and methods. Physical modeling of the interaction process of freak wave with a marine floating structure was conducted in a deep seakeeping tank. Freak wave was generated by the linear superposition method of four twodimensional unidirectional regular waves with variable steepness in frequency range of 2 to 6 rad/s. To create a control signal was using special software. Wave packets were formed consisting of a sequence of a four harmonicas with a given frequency, height and duration. For parameters registration of freak wave were used string probes installed with a certain step along the length of the tank. A marine floating structure model was fixed by elastic fastening system in a window of a tow cart. For measure the motions of marine floating structure and its accelerations in define points at encounter with freak wave the contactless optic system and two-component acceleration sensors (accelerometers) were used. Cases of structure interaction with freak wave at different course angles and speeds were considered. Main results. As result of physical experimental data of floating structure motions in the interaction with freak wave in conditions of regular sea state at five course angles with speed and without speed were obtained. Dependencies of roll, pitch and heave motions at different course angles and various speeds were built. Similar dependencies of vertical and transverse accelerations on a stem also were built. Comparative analysis of results with data, which were obtained on intensive irregular sea state (spectrum JONSWAP) at identical experiment conditions, and also with foreign results was carried out. Conclusions. The greatest roll and maximum accelerations are registered at alongside position to abnormal wave, but cargo vessel has a sufficient reserve of dynamic stability to withstand such an impulse effect. The values of roll motion and accelerations on irregular sea state are close to the parameters measured at freak wave effect. This similarity is explained by rocking effect of periodic impact of irregular sea state, the proximity of natural period of roll oscillations to average period of waves and sufficiently high waves. In comparison with foreign researches, a wider range of heading angles and speeds is considered, and data about accelerations in a stem are obtained.

Abstract In this paper, an algorithm for estimating the best distribution about data containing uncertainties is proposed. The proposed algorithm combines sequence statistical modeling (SSM) and a method for determining the minimum experimental data. SSM is a method for selecting the best distribution about data using a goodness of fit (GoF) test and a comparison of the likelihood. The method used to determine the minimum experimental data determines the minimum data needed to an estimate the best distribution. The SSM presented herein is a method for selecting a suitable data distribution when considering only a parametric distribution. Thus, in this paper, the SSM was improved in order to select the correct distribution of both parametric and non-parametric distributions simultaneously. In addition, with the existing method for determining the minimum data, the data should be added based on actual experiments when the results data show an insufficient number, and there is a limitation in that the designers cannot broadly identify the data required. To overcome this limitation, SSM and random sampling are applied to the method to determine the minimum data, and thereby, ensure that the designer knows the approximate minimum data needed. To verify the validity of the proposed algorithm, it was applied to a real world case study on determining multiple statistical parameters in the bolt fastening problem. The sequence of verification methods used is as follows: First, the best distribution of the bearing surface and thread friction coefficient estimated by the proposed algorithm and based on a normal distribution are selected as comparison targets. Second, the bearing surface and thread friction coefficient data are sampled within the 95% confidence interval of the two distributions. Third, the reliability of the sampled friction coefficient data are compared using a Monte-Carlo simulation and an equation to calculate the bolt fastening force. In this study, the effectiveness of the proposed algorithm is validated. Highlights The algorithm to determine appropriate probability distribution of data is proposed. The sequential statistical modeling is improved to consider both parametric and non-parametric distribution. The method to determine minimum data is improved to verify sufficiency of data without actual experiments. The effectiveness and validation of the proposed algorithm is verified using the bolt-fastening data.

A typical aircraft panel is the assembly consisting of a multitude of thin and lightweight compliant parts. In panel assembly process, part-to-part locating scheme has been widely adopted in order to reduce fixtures. By this locating scheme, a part is located onto the pre-fixed part/subassembly by determinant assembly (DA) holes, and temporary fasteners (e.g., spring pin) are used for joining these DA hole-hole pairs. The temporary fasteners can fasten DA hole-hole pairs in the axial and radial directions of DA holes. The fastening in the radial directions is realized by the expansion of temporary fasteners. Although the usage of temporary fasteners helps reduce the positional differences between hole-hole pairs, their clamping forces thereby may lead to elastic deformation of compliant parts/subassemblies. Limited research has been conducted on such elastic deformation produced by temporary fastener and its influence on assembly dimensional quality. This paper proposes a novel rigid-compliant variation analysis method for aircraft panel assembly, incorporating the deformation in part-to-part locating process. Based on the kinematic theory and linear elasticity deformation assumption, the variation propagation through the locating process, as well as the entire assembly process of an aircraft panel, is formulated. Then, the statistical variation analysis is performed with Monte Carlo (MC) simulation. Finally, the proposed method is validated by a case study. The result shows the deformation in the part-to-part locating process significantly impacts the assembly variations, and our method can provide a more accurate and reliable prediction.

Introduction: The topic of the article is "Analysis of cargo securing in road transport". It consists of an analytical part and a research part, the assumption of which is to conduct a survey among people who have passed a number of requirements allowing to obtain the title of a professional driver. The subject of the work is the analysis of the most important issues related to cargo securing and securing means used in road transport of cargo, which are supported by the relevant legal acts [1,2]. Aims: The aim of the research was to analyze the securing of loads in road transport and to check the knowledge of drivers of heavy goods vehicles professionally transporting loads by road on a given topic. The respondents are both drivers employed in nearby transport companies (Zakład Rolniczo-Przemysłowego "Farmutil HS", PHUS Eksport-Import Transpil Spedition Waldemar Bocheński, PUH "Gólcz i Sons" Mieczysław Gólcz, Martrans, AGA-Guderski Transport & Logistyka) and drivers, who are members of transport groups on Facebook The research lasted 3 months and covered the period from January 7, 2020 to April 7, 2020. Research Object: The subject of research is a number of issues related to loads on the means of transport, i.e. legal regulations, fastening accessories, methods of fastening. Drivers answering according to their knowledge reveal a practical perspective on securing and transporting loads. The three-month survey period resulted in 230 forms returned. The majority of respondents are men in the number of 214 people (93%). Only 16 women took part in the survey, which constitutes 7% of all respondents. The difference between the representatives of both sexes is great, which suggests that the profession of a driver is performed to a greater extent by men. Education can be a factor indicating the level of knowledge of the respondent. More than half of the respondents declared their education as secondary - 135 people (59%), then 48 people (21% chose the answer higher, basic - 39 people (17%), primary - 6 people (2%). 2 people (1%) completed their education at lower secondary school. Due to the length of service, the respondents can be divided into 6 groups. The most numerous group of 88 people (38%) are drivers who have been working in the profession for one to four years. Among the respondents there were 60 people (26%) with 5-10 years of work experience, then 43 people (19%) working 11-20 years, 24 people (10%) working less than a year, while 11 people (5%) were employed with transporting loads from 21 to 30 years. Only 4 people (2%) of the respondents can boast over 30 years of professional experience. The total length of the employment periods should indicate the level of knowledge and experience gained. The graph shows that drivers with various years of service took part in the survey, which has a positive impact on the accuracy of the results. In conclusion, the largest group of people was respondents who answered 1-4 years, which means that the road transport department has developed, and this resulted in an increase in the demand for people authorized to drive heavy goods vehicles. Methodology: Before the actual study, a pilot study was performed. It was aimed at acquiring preliminary knowledge about the studied community and testing the correctness of the questionnaire. A questionnaire survey was used to conduct the research. There were 15 single-choice closed questions and 10 open-ended questions in the survey. Some questions included photos. The complete questionnaire was made available through the Facebook social network on transport thematic groups gathering professional drivers and delivered to the transport companies previously discussed. Results: The survey was aimed at extracting the knowledge of professional drivers traveling both in Poland and other European countries about the securing of loads in road transport. The questionnaires included a properly prepared pool of questions and research techniques, which are also important for the accuracy and reliability of the research. The questions were arranged and edited in a clear and legible manner for the respondent, both in electronic and paper form. The tools used are closed-ended questions and open-ended questions with photos. The main part of the study was conducted on 230 respondents. It turned out that drivers do not have sufficient knowledge in the area in which they operate on a daily basis. Some drivers refused to answer the questionnaires, even knowing that their answers would be anonymous or they had no knowledge about it. As the survey shows, more than half of the respondents did not participate in any educational form related to cargo securing. The problem may result from the savings of the people managing the enterprise, as well as the reluctance of drivers to improve their own qualifications. Most of the respondents do not use the aids and measuring instruments available on the market to check the necessary amount of fixing means to ensure the safety of other road users. The tabular or template method of determining the number of lashings eliminates the need to use mathematical formulas, which could be problematic for some professional drivers. These are measures that improve the work and make it easier without the need to perform complex calculations. In the course of the research, difficulties arose in the form of the apparent reluctance of professional drivers to fill out an anonymous questionnaire. Unfortunately, some companies also refused to take part in the survey. It can be assumed that this was caused by the fear of the consequences that could be drawn by the legislator or the fear of the overall result of the study in the case of a specific company. Conclusion: It is required from transport to be effective, and thus profitable and safe, and it is conditioned by the proper securing of the cargo. To sum up, it can be stated that the essence of securing loads in road transport is the appropriate selection of securing means, securing methods and available security systems so that the cargo with a specific weight, shape, plasticity and other own characteristics is immobilized on a properly selected loading surface and prevents its movement. The material collected in the course of the research and the analyzes carried out show that professional drivers have insufficient knowledge in the field of load securing. The problem of poor knowledge of the subject, externalized among drivers, is a significant problem that may lead to dangerous road situations and may generate unnecessary costs in the enterprise. In this situation, its managers should react. An example of a response to such signals may be the employment of a person providing consultancy services in the field of cargo securing, training or audits in transport companies. Retraining professional drivers or organizing training for those who are just taking their first steps in the profession is crucial. A person who becomes aware of the scale of the risk and shows the visual effects of road accidents with greater diligence and accuracy will secure the load that has been assigned to him and make sure that he drives to the road with a vehicle that does not pose a threat. Lashing loads is a field of transport in which an individual approach should be taken to the load taken for transport. Standard mathematical formulas are helpful for this. But not all charges can be formulated and act schematically. Various loads of different shapes, sizes and other own characteristics are a challenge for people responsible for their safe transport. The driver carrying the load can make sure that it has been properly secured, without the need to use complicated mathematical formulas. It may turn out to be problematic for him, which is why publications have been made to facilitate these issues. Each type of trailer has a different security method. The driver, acquiring the license, is obliged to have knowledge in this topic and the translation of the lack of competence is groundless. On the current labor market, entrepreneurs dynamically develop their fleet following the prospect of a potential customer, which results in the transport of various goods. They are looking for specialized drivers with skills, failure to improve qualifications may result in job loss. Load securing is a field of transport that is constantly expanding its range. Demanding from the people involved to create innovative solutions to emerging problems posed by loads during transport. The guarantee of the search for the most effective methods of fastening and auxiliary devices is the growing transport and the willingness to transport various loads. To conclude the considerations undertaken in this paper, it should be stated that the common goal of people involved in the transport of goods should be to improve the safety of all road users and to comply with applicable road regulations.