The Experts below are selected from a list of 94863 Experts worldwide ranked by ideXlab platform
Matteo Ciccotti - One of the best experts on this subject based on the ideXlab platform.
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mechanics of an adhesive tape in a zero degree peel test effect of large Deformation and material nonlinearity
Soft Matter, 2018Co-Authors: Helen Minsky, Costantino Creton, Matteo CiccottiAbstract:The common pressure sensitive adhesive (PSA) tape is a composite consisting of a stiff backing layer and a soft adhesive layer. A simple and common way to test how adhesive tapes respond to large shear Deformations is the zero degree peel test. Because the backing is very stiff compared to the adhesive layer, the region where the adhesive layer is subjected to large shear can be hundreds of times its thickness. We use a large Deformation hyperelastic model to study the stress and Deformation fields in the adhesive layer in this test. We present a closed-form solution for the stress field in the adhesive layer and use this solution to determine how load is transferred from the backing layer to the adhesive. Our analytical model is then compared with finite element results, and except for a small region near the peel front, the predicted stress and Deformation agree well with the finite element model. Interestingly, we find very different results from the classical linear theory established by Kaelble. In particular for large Deformations, our analysis shows that the lateral stresses (parallel to the rigid substrate) are much larger than the shear stress in the adhesive layer. The discrepancy in the stress State and the Deformation State with the linear theory is particularly large near the peel front, which we study with a finite element model. These new results will be very useful to interpret experiments and in particular to identify the high stress regions where failure is likely to initiate in zero-degree peel tests also called shear resistance tests in the PSA industry.
Mei Zhan - One of the best experts on this subject based on the ideXlab platform.
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research on plastic Deformation behaviour in cold ring rolling by fem numerical simulation
Modelling and Simulation in Materials Science and Engineering, 2005Co-Authors: He Yang, Mei ZhanAbstract:Cold ring rolling is an advanced but complex metal forming process under coupled effects with multi-factors, such as geometry sizes of rolls and ring blank, material, forming parameters, friction, etc. Investigating the plastic Deformation behaviour (the plastic Deformation State and its development) in the Deformation zone during the process is very significant for rapidly predicting the metal flow, controlling the quality of deformed rings and optimizing the cold ring rolling process. In this paper, a decisive factor on plastic Deformation behaviour, namely the average amount of feed per revolution , has firstly been ascertained. Then a functional relation, between and various process parameters, has been now established. Lastly, through 3D numerical simulation based on the elastic–plastic dynamic explicit FEM under the ABAQUS software environment, it has been found that there are three kinds of plastic Deformation behaviours during cold ring rolling operation. One is that the material in the Deformation zone entirely comes into the plastic Deformation State at the early stage of the process. Two is that the material in the Deformation zone gradually comes into the plastic Deformation State during the process. And last is that at the end of the process, there is still a rigid zone in elastic Deformation or small plastic strain State near the middle radius of the ring blank. Based on this, the influence of plastic Deformation behaviours on metal flow, the degrees of inhomogeneous Deformation of ring and force and power parameters in the cold ring rolling process have been explored. The achievements of this study thoroughly reveal the Deformation mechanism of cold ring rolling and provide an important basis for the optimization of process parameters and precise control of the cold ring rolling process.
Caglar Oskay - One of the best experts on this subject based on the ideXlab platform.
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Eigenstrain based reduced order homogenization for polycrystalline materials. Comput. Methods
2016Co-Authors: Xiang Zhang, Caglar OskayAbstract:In this manuscript, an eigenstrain based reduced order homogenization method is devel-oped for polycrystalline materials. A two-scale asymptotic analysis is used to decompose the original equations of polycrystal plasticity into micro- and macroscale problems. Eigenstrain based representation of the inelastic response field is employed to approximate the microscale boundary value problem using an approximation basis of much smaller order. The reduced or-der model takes into account the grain-to-grain interactions through influence functions that are numerically computed over the polycrystalline microstructure. The proposed approach is also endowed with a hierarchical model improvement capability that allows accurate rep-resentation of stress and Deformation State within subgrains. The proposed approach was implemented and its performance was assessed against crystal plasticity finite element simula-tions. Numerical studies point to the capability to efficiently compute the mechanical response of the polycrystal RVEs with good accuracy and the ability to capture stress risers near grain boundaries
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eigenstrain based reduced order homogenization for polycrystalline materials
Computer Methods in Applied Mechanics and Engineering, 2015Co-Authors: Xiang Zhang, Caglar OskayAbstract:Abstract In this manuscript, an eigenstrain based reduced order homogenization method is developed for polycrystalline materials. A two-scale asymptotic analysis is used to decompose the original equations of polycrystal plasticity into micro- and macroscale problems. Eigenstrain based representation of the inelastic response field is employed to approximate the microscale boundary value problem using an approximation basis of much smaller order. The reduced order model takes into account the grain-to-grain interactions through influence functions that are numerically computed over the polycrystalline microstructure. The proposed approach is also endowed with a hierarchical model improvement capability that allows accurate representation of stress and Deformation State within subgrains. The proposed approach was implemented and its performance was assessed against crystal plasticity finite element simulations. Numerical studies point to the capability to efficiently compute the mechanical response of the polycrystal RVEs with good accuracy and the ability to capture stress risers near grain boundaries.
Helen Minsky - One of the best experts on this subject based on the ideXlab platform.
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mechanics of an adhesive tape in a zero degree peel test effect of large Deformation and material nonlinearity
Soft Matter, 2018Co-Authors: Helen Minsky, Costantino Creton, Matteo CiccottiAbstract:The common pressure sensitive adhesive (PSA) tape is a composite consisting of a stiff backing layer and a soft adhesive layer. A simple and common way to test how adhesive tapes respond to large shear Deformations is the zero degree peel test. Because the backing is very stiff compared to the adhesive layer, the region where the adhesive layer is subjected to large shear can be hundreds of times its thickness. We use a large Deformation hyperelastic model to study the stress and Deformation fields in the adhesive layer in this test. We present a closed-form solution for the stress field in the adhesive layer and use this solution to determine how load is transferred from the backing layer to the adhesive. Our analytical model is then compared with finite element results, and except for a small region near the peel front, the predicted stress and Deformation agree well with the finite element model. Interestingly, we find very different results from the classical linear theory established by Kaelble. In particular for large Deformations, our analysis shows that the lateral stresses (parallel to the rigid substrate) are much larger than the shear stress in the adhesive layer. The discrepancy in the stress State and the Deformation State with the linear theory is particularly large near the peel front, which we study with a finite element model. These new results will be very useful to interpret experiments and in particular to identify the high stress regions where failure is likely to initiate in zero-degree peel tests also called shear resistance tests in the PSA industry.
He Yang - One of the best experts on this subject based on the ideXlab platform.
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research on plastic Deformation behaviour in cold ring rolling by fem numerical simulation
Modelling and Simulation in Materials Science and Engineering, 2005Co-Authors: He Yang, Mei ZhanAbstract:Cold ring rolling is an advanced but complex metal forming process under coupled effects with multi-factors, such as geometry sizes of rolls and ring blank, material, forming parameters, friction, etc. Investigating the plastic Deformation behaviour (the plastic Deformation State and its development) in the Deformation zone during the process is very significant for rapidly predicting the metal flow, controlling the quality of deformed rings and optimizing the cold ring rolling process. In this paper, a decisive factor on plastic Deformation behaviour, namely the average amount of feed per revolution , has firstly been ascertained. Then a functional relation, between and various process parameters, has been now established. Lastly, through 3D numerical simulation based on the elastic–plastic dynamic explicit FEM under the ABAQUS software environment, it has been found that there are three kinds of plastic Deformation behaviours during cold ring rolling operation. One is that the material in the Deformation zone entirely comes into the plastic Deformation State at the early stage of the process. Two is that the material in the Deformation zone gradually comes into the plastic Deformation State during the process. And last is that at the end of the process, there is still a rigid zone in elastic Deformation or small plastic strain State near the middle radius of the ring blank. Based on this, the influence of plastic Deformation behaviours on metal flow, the degrees of inhomogeneous Deformation of ring and force and power parameters in the cold ring rolling process have been explored. The achievements of this study thoroughly reveal the Deformation mechanism of cold ring rolling and provide an important basis for the optimization of process parameters and precise control of the cold ring rolling process.