Academic literature on the topic 'Plates theory'

With employing the transverse shear deformation theory and von Karman plate theory, the nonlinear static behavior of a simply supported rectangular magnetoelectroelastic plates is investigated. According to the Maxwell’s equations, when applying the magnetoelectric load on the plate’s surfaces and neglecting the in-plane electric and magnetic fields in thin plates, the electric and magnetic potentials varying along the thickness direction of the magnetoelectroelastic plates are determined. The nonlinear differential equations for magnetoelectroelastic plates are established based on the Hamilton’s principle. The Galerkin procedure furnishes an infinite system of differential equations into algebraic equations. In the numerical calculations, the effects of the nonlinearity and span-thickness ratio on the nonlinear load-deflection curves and electric/magnetic potentials for magnetoelectroelastic plates are discussed.

Auxetic solids are materials that exhibit negative Poisson’s ratio. This paper evaluates the maximum stresses in point-loaded (a) auxetic plates on conventional elastic foundation, (b) conventional plates on auxetic elastic foundation, and (c) auxetic plates on auxetic elastic foundation vis-à-vis conventional plates on conventional elastic foundation. Using thick plate theory for infinite plates on elastic foundation, it was found that in most cases the auxetic plates and auxetic foundation play the primary and secondary roles, respectively, in reducing the plate’s maximum stresses. It is herein suggested that, in addition to materials selection technique and other design considerations, the use of auxetic plates and/or auxetic foundation be introduced for reducing stresses in plates on elastic foundations.

This study investigates the free vibration behavior of porous metal foam plates using the Quasi-3D refined plate theory. We consider three types of pores across the plate thickness: uniform, symmetric, and asymmetric distributions. Besides, the metal foam plate is reinforced by a Winkler-Pasternak foundation. By employing the variational principle and Quasi-3D refined theory, we derive the weak form for free vibration analysis. The Quasi-3D theory is essential for analyzing plates, as it accurately captures transverse shear and normal deformations, which are vital for understanding the behavior of thick and moderately thick plates. Unlike simpler models, it provides a detailed representation of stress and strain distributions across the plate’s thickness, enabling precise modeling of complex structural behaviors. The natural frequency of the porous metal foam plates is determined by solving the explicit governing equation using the isogeometric approach. Additionally, we examine how the porous coefficient, porous distribution, and geometry impact the vibrational frequency of the porous metal foam plate.

In the article, constructions made of orthotropic multilayer composite material, in particular, layered orthotropic plates are considered. Numerical modeling and analysis of the stress-strain state for the plates are carried out on the basis of one version for the refined theory of layered plates. The bending problems for plates of medium thickness and thin multilayer plates of symmetric and asymmetric structures are investigated. All studies are conducted taking into account the properties of orthotropy and multilayering for the composite material from which the plates are made. The general algorithm for the numerical calculation of the stress-strain state for layered plates with orthotropic layers is developed on the basis of the finite difference method. This algorithm is implemented on a PC by a software package.

This research aims to provide the numerical analysis solution of symmetric angle ply plates using higher-order shear deformation theory (HSDT). The vibration of symmetric angle ply composite plates is analyzed using differential equations consisting of supplanting and turning functions. These supplanting and turning functions are numerically approximated through spline approximation. The obtained global eigenvalue problem is solved numerically to find the eigenfrequency parameter and a related eigenvector of spline coefficients. The plates of different constituent components are used to study the parametric effects of the plate’s aspect ratio, side-to-thickness ratio, assembling sequence, number of composite layers, and alignment of each layer on the frequency of the plate. The obtained results are validated by existing literature.

The paper treats the theory of thin coated plates under a variety of load and deposition conditions. In addition to some bending problems caused by external load the so called Stoney-equation is considered.

This thesis presents two studies on elastic plates. In the first study, we discuss the choice of elastic energies for thin plates and shells, an unsettled issue with consequences for much recent modeling of soft matter. Through consideration of simple deformations of a thin body in the plane, we demonstrate that four bulk isotropic quadratic elastic theories have fundamentally different predictions with regard to bending behavior. At finite thickness, these qualitative effects persist near the limit of mid-surface isometry, and not all theories predict an isometric ground state. We discuss how certain kinematic measures that arose in early studies of rod mechanics lead to coherent definitions of stretching and bending, and promote the adoption of these quantities in the development of a covariant theory based on stretches rather than metrics. In the second work, the effects of in-plane swelling gradients on thin, anisotropic plates are investigated. We study systems with a separation of scales between bending energy terms. Warped equilibrium shapes are described by two parameters controlling the spatial "rolling up'' and twisting of the surface. Shapes within this two-parameter space are explored, and it is shown that shapes will either be axisymmetric or twisted depending on swelling function parameters and material anisotropy. In some axisymmetric shapes, pitchfork bifurcations to twisted solutions are observed by varying these parameters. We also show that a familiar soft mode of the catenoid to helicoid transformation of an isotropic material no longer exists with material anisotropy.<br>Master of Science<br>This thesis presents two studies on the subject of thin, elastic bodies, otherwise known as plates. Plate theory has important applications in many areas of life, ranging from the design and construction of civil structures to the mechanics of wrinkling sheets. In the first work, we discuss how different elastic plate theories have qualitatively different predictions on how a plate will behave when bent. We discuss the different physical implications of each model, and relate our findings to previous studies. Additionally, we promote the use of certain technical measures in the study of plates corresponding to the most coherent definitions of bending and stretching. In the second work, we study the effects of in-plane swelling gradients on elastic plates whose material stiffnesses vary with direction. Inspired by wood panels that warp when exposed to moisture, we model elastic plates exposed to various swelling patterns and determine the resulting warped shapes. We find that some shapes are axisymmetric, while others prefer to twist when exposed to moisture-induced swelling. By varying certain parameters of the swelling functions, or by increasing the material fiber stiffness, we also find a qualitative change in shape from an axisymmetric to a twisted surface.

Creep deformation in welded pipes and plates is of particular importance in the power industries. Most failures of welded pipes occur in the type IV region at the boundary with the parent material, which is relatively much harder. This thesis extends the work of Nicol (1985), Hawkes (1989) and Newman (1993) on the Cosserat theory of plates and shells, and has two major aims. The first is to develop the work of Hawkes to model successfully the strain rates in four-zone, thickwalled welded pipes. It is possible to determine the effects that the thickness of the pipe wall, the radius of the pipe and the creep index, n, in Norton's law have on the strain-rate distribution throughout the pipe. Using Continuum Damage Mechanics and this Cosserat model, the position and time to rupture in welded pipes is then calculated. The second aim of this thesis is to develop further the initial modelling work of Nicol (1985) and Hawkes (1989) by obtaining some simple perturbation models for both welded pipes and plates. The results obtained with the perturbation solutions are then compared with the numerical solutions of Newman (1993) for a plate and the numerical solutions derived in this thesis for a pipe.

In recent years advances in technology have allowed the transition of composite structures from secondary to primary structural components. Consequently, a lot of applications demand development of thicker composite structures to sustain heavier loads. Typical sandwich panels consist of two thin metallic or composite face sheets separated by a honeycomb or foam core. This configuration gives the sandwich panel high stiffness and strength and enables excellent energy absorption capabilities with little resultant weight penalty. This makes sandwich structures a preferred design for a lot of applications including aerospace, naval, wind turbines and civil industries. Most aerospace structures can be analyzed using shell and plate models and many such structures are modeled as composite sandwich plates and shells. Accurate theoretical formulations that minimize the CPU time without penalties on the quality of the results are thus of fundamental importance. The classical plate theory (CPT) and the first order shear deformation theory (FSDT) are the simplest equivalent single-layer models, and they adequately describe the kinematic behavior of most laminates where the difference between the stiffnesses of the respective phases is not huge. However, in the case of sandwich structures where the core is a much more compliant and softer material as compared to the face sheets the results from CPT and FSDT becomes highly inaccurate. Higher order theories in such cases can represent the kinematics better, may not require shear correction factors, and can yield much more accurate results. An advanced Extended Higher-order Sandwich Panel Theory (EHSAPT) which is a two-dimensional extension of the EHSAPT beam model that Phan presented is developed. Phan had extended the HSAPT theory for beams that allows for the transverse shear distribution in the core to acquire the proper distribution as the core stiffness increases as a result of non-negligible in-plane stresses. The HSAPT model is incapable of capturing the in-plane stresses and assumes negligible in-plane rigidity. The current research extends that concept and applies it to two-dimensional plate structures with variable aspect ratios. The theory assumes a transverse displacement in the core that varies as a second order equation in z and the in-plane displacements that are of third order in z, the transverse coordinate. This approach allows for five generalized coordinates in the core (the in-plane and transverse displacements and two rotations about the x and y-axes respectively). The major assumptions of the theory are as follows: 1) The face sheets satisfy the Euler-Bernoulli assumptions, and their thicknesses are small compared to the overall thickness of the sandwich section; they undergo small strains with moderate rotations. 2) The core is compressible in the transverse and axial directions; it has in-plane, transverse and shear rigidities. 3) The bonding between the face sheets and the core is assumed to be perfect. The kinematic model is developed by assuming a displacement field for the soft core and then enforcing continuity of the displacement field across the interface between the core and facesheets. The constitutive relations are then defined, and variational and energy techniques are employed to develop the governing equations and associated boundary conditions. A static loading case for a simply supported sandwich plate is first considered, and the results are compared to existing solutions from Elasticity theory, Classical Plate Theory (CPT) and First-Order Shear Deformation Plate Theory (FSDT). Subsequently, the governing equations for a dynamic analysis are developed for a laminated sandwich plate. A free vibration problem is analyzed for a simply supported laminated sandwich plate, and the results for the fundamental natural frequency are compared to benchmark elasticity solutions provided by Noor. After validation of the new Extended Higher Order Sandwich Panel Theory (EHSAPT), a parametric study is carried out to analyze the effect of variation of various geometric and material properties on the fundamental natural frequency of the structure. After the necessary verification and validation of the theory by comparing static and free vibration results to elasticity solutions, a nonlinear static analysis for square and rectangular plates is carried out under various sets of boundary conditions. The analysis was carried out using variational techniques, and the Ritz method was used to find an approximate solution. The kinematics were developed for a sandwich plate undergoing small strain and moderate rotations and nonlinear strain displacement relations were evaluated. Approximate and assumed solutions satisfying the geometric boundary conditions were developed and substituted in the total potential energy relations. After carrying out the spatial integrations, the total potential energy was then minimized with respect to the unknown coefficients in the assumed solution resulting in nonlinear simultaneous algebraic equations for the unknown coefficients. The simultaneous nonlinear equations were then solved using the Newton-Raphson method. A convergence study was carried out to study the effect of varying the number of terms in the approximate solution on the overall result and rapid convergence was observed. The rapid convergence can be attributed to the fact that the assumed approximate solution not only satisfies the geometric boundary conditions of the problem but also the natural boundary conditions. During calculations four cases of boundary conditions were considered 1) Simply Supported with moveable edges. 2) Simply Supported with fixed edges. 3) Clamped with moveable edges. 4) Clamped with fixed edges. For movable boundary conditions, in-plane displacements along the normal direction to the supported edges are allowed whereas the out-of-plane displacement is fixed. For the immovable boundary condition cases, the plate is prevented from both in-plane and out-of-plane displacements along the edges. For the simply supported cases rotations about the tangential direction are allowed, and for the clamped cases no rotations are allowed.In recent years advances in technology have allowed the transition of composite structures from secondary to primary structural components. Consequently, a lot of applications demand development of thicker composite structures to sustain heavier loads. Typical sandwich panels consist of two thin metallic or composite face sheets separated by a honeycomb or foam core. This configuration gives the sandwich panel high stiffness and strength and enables excellent energy absorption capabilities with little resultant weight penalty. This makes sandwich structures a preferred design for a lot of applications including aerospace, naval, wind turbines and civil industries. Most aerospace structures can be analyzed using shell and plate models and many such structures are modeled as composite sandwich plates and shells. Accurate theoretical formulations that minimize the CPU time without penalties on the quality of the results are thus of fundamental importance. The classical plate theory (CPT) and the first order shear deformation theory (FSDT) are the simplest equivalent single-layer models, and they adequately describe the kinematic behavior of most laminates where the difference between the stiffnesses of the respective phases is not huge. However, in the case of sandwich structures where the core is a much more compliant and softer material as compared to the face sheets the results from CPT and FSDT becomes highly inaccurate. Higher order theories in such cases can represent the kinematics better, may not require shear correction factors, and can yield much more accurate results. An advanced Extended Higher-order Sandwich Panel Theory (EHSAPT) which is a two-dimensional extension of the EHSAPT beam model that Phan presented is developed. Phan had extended the HSAPT theory for beams that allows for the transverse shear distribution in the core to acquire the proper distribution as the core stiffness increases as a result of non-negligible in-plane stresses. The HSAPT model is incapable of capturing the in-plane stresses and assumes negligible in-plane rigidity. The current research extends that concept and applies it to two-dimensional plate structures with variable aspect ratios. The theory assumes a transverse displacement in the core that varies as a second order equation in z and the in-plane displacements that are of third order in z, the transverse coordinate. This approach allows for five generalized coordinates in the core (the in-plane and transverse displacements and two rotations about the x and y-axes respectively). The major assumptions of the theory are as follows: 1) The face sheets satisfy the Euler-Bernoulli assumptions, and their thicknesses are small compared to the overall thickness of the sandwich section; they undergo small strains with moderate rotations. 2) The core is compressible in the transverse and axial directions; it has in-plane, transverse and shear rigidities. 3) The bonding between the face sheets and the core is assumed to be perfect. The kinematic model is developed by assuming a displacement field for the soft core and then enforcing continuity of the displacement field across the interface between the core and facesheets. The constitutive relations are then defined, and variational and energy techniques are employed to develop the governing equations and associated boundary conditions. A static loading case for a simply supported sandwich plate is first considered, and the results are compared to existing solutions from Elasticity theory, Classical Plate Theory (CPT) and First-Order Shear Deformation Plate Theory (FSDT). Subsequently, the governing equations for a dynamic analysis are developed for a laminated sandwich plate. A free vibration problem is analyzed for a simply supported laminated sandwich plate, and the results for the fundamental natural frequency are compared to benchmark elasticity solutions provided by Noor. After validation of the new Extended Higher Order Sandwich Panel Theory (EHSAPT), a parametric study is carried out to analyze the effect of variation of various geometric and material properties on the fundamental natural frequency of the structure. After the necessary verification and validation of the theory by comparing static and free vibration results to elasticity solutions, a nonlinear static analysis for square and rectangular plates is carried out under various sets of boundary conditions. The analysis was carried out using variational techniques, and the Ritz method was used to find an approximate solution. The kinematics were developed for a sandwich plate undergoing small strain and moderate rotations and nonlinear strain displacement relations were evaluated. Approximate and assumed solutions satisfying the geometric boundary conditions were developed and substituted in the total potential energy relations. After carrying out the spatial integrations, the total potential energy was then minimized with respect to the unknown coefficients in the assumed solution resulting in nonlinear simultaneous algebraic equations for the unknown coefficients. The simultaneous nonlinear equations were then solved using the Newton-Raphson method. A convergence study was carried out to study the effect of varying the number of terms in the approximate solution on the overall result and rapid convergence was observed. The rapid convergence can be attributed to the fact that the assumed approximate solution not only satisfies the geometric boundary conditions of the problem but also the natural boundary conditions. During calculations four cases of boundary conditions were considered 1) Simply Supported with moveable edges. 2) Simply Supported with fixed edges. 3) Clamped with moveable edges. 4) Clamped with fixed edges. For movable boundary conditions, in-plane displacements along the normal direction to the supported edges are allowed whereas the out-of-plane displacement is fixed. For the immovable boundary condition cases, the plate is prevented from both in-plane and out-of-plane displacements along the edges. For the simply supported cases rotations about the tangential direction are allowed, and for the clamped cases no rotations are allowed.

The bifurcation phenomenon occurring in twisted square plates with free edges subject to contrary self-equilibrating corner loading was examined. In order to eliminate lateral deflection of the test plates due to their own weight, a special loading apparatus was constructed which held the plates in a vertical plane. The complete strain field occurring at the plate centre was measured using two strain gauge rosettes mounted on opposing sides of the plate at the centre. Principal curvatures were calculated and related to corner load for several plates with differing edge length/thickness ratios. A Southwell plot was used relating mean curvature to the ratio mean curvature/Gaussian curvature, from which the Gaussian curvature occurring at bifurcation was determined. The critical dimensionless twist ka was then calculated for each plate size. It was found that there is a linear relation between the critical dimensionless twist ka occurring at bifurcation, and the thickness to edge length ratio h/a ratio, specifically: ka = 10.8h/a.<br>Applied Science, Faculty of<br>Mechanical Engineering, Department of<br>Graduate

Treated herein is the elastic buckling of circular plates based on the Reddy plate theory. This plate theroy extends the Kirchhoff (or the classical thin) plate theory to allow for the effect of transverse shear deformation. Unlike the Mindlin’s shear deformation plate theory, there is no need for a shear correction factor in the Reddy plate theory. In this paper, exact buckling solutions are derived for circular plates whose edges are simply supported and elastically restrained against rotation as well. This general edge condition includes the classical simply supported and clamped edges at the limiting, values of the elastic rotational restraint constant. The buckling solutions are expressed in terms of the well-known Kichhoff buckling solutions. A comparison of buckling loads between the Mindlin, Reddy and three-dimensional elasticity plates is also given.

In flexible multibody systems, many components are often approximated as plates. More often that not, classical plate theories, such as Kirchhoff or Reissner-Mindlin plate theory, form the basis of the analytical development for plate dynamics. The advantage of this approach is that it leads to a very simple kinematic representation of the problem: the plate’s normal material line is assumed to remain straight and its displacement field is fully defined by three displacement and two rotation components. While such approach is capable of capturing the kinetic energy of the system accurately, it cannot represent the strain energy adequately. For instance, it is well known from three-dimensional elasticity theory that the normal material line will warp under load for laminated composite plates, leading to a three-dimensional deformation state that generates a complex stress state. To overcome this problem, several high-order and refined plate theory were proposed. While these approaches work well for some cases, they typically lead to inefficient formulation because they introduce numerous additional variables. This paper presents a different approach to the problem, which is based on a finite element discretization of the normal material line, and relies of the Hamiltonian formalism of obtain solutions of the governing equations. Polynomial solutions, also known as central solutions, are obtained that propagate over the entire span of the plate.

In structural analysis, many components are approximated as plates. More often that not, classical plate theories, such as Kirchhoff or Reissner-Mindlin plate theories, form the basis of the analytical developments. The advantage of these approaches is that they leads to simple kinematic descriptions of the problem: the plate’s normal material line is assumed to remain straight and its displacement field is fully defined by three displacement and two rotation components. While such approach is capable of capturing the kinetic energy of the system accurately, it cannot represent the strain energy adequately. For instance, it is well known from three-dimensional elasticity theory that the normal material line will warp under load for laminated composite plates, leading to three-dimensional deformations that generate complex stress states. To overcome this problem, several high-order, refined plate theories have been proposed. While these approaches work well for some cases, they often lead to inefficient formulations because they introduce numerous additional variables. This paper presents a different approach to the problem: based on a finite element semi-discretization of the normal material line, plate equations are derived from three-dimensional elasticity using a rigorous dimensional reduction procedure.

Abstract. Composite structures offer a practical approach for many engineering applications, but their design is complex and can result in excessive sizing due to limitations in current modeling techniques. BTDs minimize the number of unknown variables in a kinematic theory for desired accuracy or for a fixed error in the Carrera Unified Formulation. This paper presents a method for computing Best Theory Diagrams (BTDs) for laminated composite plates using Genetic Algorithms (GA). As reported in previous papers by the authors, a multi-objective optimization technique using a GA is applied to build BTDs for a given structural problem. The plate models stresses and displacements are compared to those of a reference solution, and a plate model performance is quantified in terms of the number of unknown variables, the mean error and standard deviation of the stresses and displacements. Also, with the objective of reducing the computational time, a Neural-Networks (NN) was trained to reproduce the mean error and standard deviation of the stresses and displacements for any plate model refined from a reference plate model is addressed. Numerical simulations were computed for laminated composite plates with previously uninvestigated boundary conditions and compare computational time for BTD calculation. The preliminary results show that the use of multi-objective GA plus NN method reduces considerably the computation time to build BTDs.

According to “Contingency Theory” and several researches, there is no absolutely conclusive result to show that there is a best control system for all firms that fits all types of competitive strategy. Also, based on “Expentancy Theory” , in order to motivate employee, the compensation plans have to cover all performance measures that fully reflect employee’s effort. Hence, this case-based research is set up for the purpose of studying the consistency of firm’ s performance evaluation and compensation plans with competitive strategy. All 285 of MBA students at the Faculty of Commerce and Accountancy, Chulalongkorn University, Thailand, are the experimental units. The controlled group with 141 regular MBA students are subdivided into two groups as low-cost group and product-differentiation group. Then each group is subdivided into two more sub groups as CEO and MD groups. For the treated groups with 144 executive MBA students, subdivision is done in the same manner as the controlled group. The experiment is set up to evaluate whether competitive strategy affects weights placed on performance measures used for firm’ s performance evaluation and compensation plans. Also, it is set up to evaluate the consistency of weights placed on performance measure for these two purposes under a given competitive strategy. The research results are as expected. That is, under low-cost strategy, a firm places more weights on financial performance measures for firm’s performance evaluation resulting in short-term oriented compensation plans and vice versa. Under product-differentiation strategy, a firm places more weights on non-financial performance measures for firm’s performance evaluation resulting in long-term oriented compensation plans and vice versa. Therefore, the consistency of two control systems are evidenced from this research. That is, for a given competitive strategy, a control system designed by first considering the appropriate firm’s performance evaluation system to match with that strategy in terms of weights placed on performance measures followed by the compensation plans will be consistent with the control system designed by first considering the appropriate compensation plans to match with that same strategy and followed by firm’ performance evaluation system. However, executives of a low-cost strategy firm significantly place more weight on “productivity” which is one of non-financial performance measures for both firm’s performance evaluation and compensation plans than those of a product-differentiation strategy firm. This means that although productivity is non-financial performance measure, it still plays crucial role for a low-cost strategy firm than a product-differentiation one. This may be due to the fact that usually low-cost strategy firms emphasis on efficiency as an important mean to reduce cost. And “productivity” is one performance measure that evaluates the efficiency of firms.

Like other bird and mammal species whose populations have been restored through conservation efforts, wild turkeys are treasured by many recreationists and outdoor enthusiasts. Wild turkeys have responded positively to wildlife habitat and population management. In some areas, however, their increased populations have led to increased damage to property and agricultural crops, and threats to human health and safety. Turkeys frequent agricultural fields, pastures, vineyards and orchards, as well as some urban and suburban neighborhoods. Because of this, they may cause damage or mistakenly be blamed for damage. Research has found that despite increases in turkey numbers and complaints, damage is often caused by other mammalian or bird species, not turkeys. In the instances where turkeys did cause damage, it was to specialty crops, vineyards, orchards, hay bales or silage pits during the winter. In cultured crops or gardens where wood chips, pine straw or other bedding materials (mulch) are placed around plants, wild turkeys sometimes scratch or dig up the material and damage plants when searching for food. Wild turkeys are a valuable game species, treasured by recreational hunters and wildlife enthusiasts.

Once upon a time, there was a place with good soil for plants and good sources of water for wild animals. Many, many plants grew there, and many wild animals made it their home. People liked it too. In fact, so many people wanted it to be their home, they built a city. The world's big cities -that are now full of skyscrapers and wide concrete avenues, and where the only wild animals live in zoos- once looked very different. Many were farms. A few were jungles or swamps. A handful were desert oases. Even today, cities cannot be separated from the natural environment. Natural ecosystems provide the resources that cities need to develop and grow, including water, clean air, soil, food, and energy.

In current bridge design specifications and evaluation manuals from the American Association of State Highway and Transportation Officials (AASHTO LRFD) (AASHTO, 2018), the detail category for base metal at the toe of transverse stiffener-to-flange fillet welds and transverse stiffener-to-web fillet welds to the direction of the web and hence, the primary stress) is Category C′. In skewed bridges or various other applications, there is sometimes a need to place the stiffener or a connection plate at an angle that is not at 90 degrees to the web. As the plate is rotated away from being 90 degrees to the web, the effective “length” of the stiffener in the longitudinal direction increases. However, AASHTO is currently silent on how to address the possible effects on fatigue performance for other angles in between these two extremes. This report summarizes an FEA study that was conducted in order to investigate and determine the fatigue category for welded attachments that are placed at angles other than 0 or 90 degrees for various stiffener geometries and thicknesses. Recommendations on how to incorporate the results into the AASHTO LRFD Bridge Design Specifications are included in this report.

The global fragmentation of production has important implications for the environment. As emerging economies increase their participation in trade, scale effects increase environmental impacts worldwide. Yet at the same time, access to international markets might help offset these impacts by increasing the efficiency of production. Existing literature suggests that trading firms tend to be more energy efficient than non-traders. However, this literature does not take into account the effect of firms’ product baskets. In this paper, we leverage a rich plantand product-level database from India to investigate the effects of importing on plant-level environmental outcomes. We first construct a measure of energy efficiency that is net of effects arising from plants’ product baskets. We then use an event study set up to compare outcomes between importers and future importers at the time of their entry into import markets. Our design takes advantage of plants’ staggered entry into importing to address issues of selection. Our findings suggest that after they start importing, plants experience increases in their energy intensity. Plants which start importing also grow larger and more productive, and diversify their product baskets. Our results suggest that access to international markets leads to gains in scale and productivity, but not in environmental performance. This finding suggests that there is an environmental cost to learning and product diversification.