This paper mainly discusses the constitutive laws of incompressible rubber-like materials and the associated finite element analysis method. By a multiplicative decomposition of the deformation gradient into distortio...This paper mainly discusses the constitutive laws of incompressible rubber-like materials and the associated finite element analysis method. By a multiplicative decomposition of the deformation gradient into distortional and dilatational parts, the YEOH mode type constitutive laws of rubber-like materials and their numerical implementation are presented. In order to deal with incompressible problems, a three-field variational principle is developed in which deformation, Jacobian and pressure field are treated independently. The connection between the three-field principle and the Hu-Wasizhu generalized variational principle is established. It is shown that the approach proposed can be degenerated to the B-bar method in the linear case. The derailed FE formulation is given in which deformation is ap proximated by isoparametric conforming element, and Jacobian and pressure by discontinuous approximation. Finally, two numerical examples are presented to show the effectiveness and reliability of the method proposed. The work in this paper provides a corner stone of FEA of this kind of problem. This paper features the combination of the multiplicative decomposition, the three-field principle and YEOH model of rubber-like materials, especially under Lagrangian description, giving an effective way for solving this kind of problems. The Lagrangian description is compatible with usually geometrically nonlinear FEM and the constitutive laws are expressed by the second Kirchhoff stress and the Green strain.展开更多
The pyroelectric effect of phase transition induced with temperature in Nb-modified Pb(Zr,Sn,Ti)O3 antiferroelectric-ferroelectric ceramics is studied. Experimental results reveal that the phase transitions are accomp...The pyroelectric effect of phase transition induced with temperature in Nb-modified Pb(Zr,Sn,Ti)O3 antiferroelectric-ferroelectric ceramics is studied. Experimental results reveal that the phase transitions are accompanied with marked pyroelectric peaks, there exists the close relation between the type of phase transition and the shape of pyroelectric peak. Because of the variations of phase transition, various pyroelectric spectra result. The pyroelectric spectrum can display the polarization effect and some inferior phase transitions with temperature variations, such as antiferroelectric AFEA-AFEB or ferroelectric FEL-FEH transition, which are not detected by the conventional dielectric measurement.展开更多
基金the National Natural Science Foundation of China(No.19632030)
文摘This paper mainly discusses the constitutive laws of incompressible rubber-like materials and the associated finite element analysis method. By a multiplicative decomposition of the deformation gradient into distortional and dilatational parts, the YEOH mode type constitutive laws of rubber-like materials and their numerical implementation are presented. In order to deal with incompressible problems, a three-field variational principle is developed in which deformation, Jacobian and pressure field are treated independently. The connection between the three-field principle and the Hu-Wasizhu generalized variational principle is established. It is shown that the approach proposed can be degenerated to the B-bar method in the linear case. The derailed FE formulation is given in which deformation is ap proximated by isoparametric conforming element, and Jacobian and pressure by discontinuous approximation. Finally, two numerical examples are presented to show the effectiveness and reliability of the method proposed. The work in this paper provides a corner stone of FEA of this kind of problem. This paper features the combination of the multiplicative decomposition, the three-field principle and YEOH model of rubber-like materials, especially under Lagrangian description, giving an effective way for solving this kind of problems. The Lagrangian description is compatible with usually geometrically nonlinear FEM and the constitutive laws are expressed by the second Kirchhoff stress and the Green strain.
文摘The pyroelectric effect of phase transition induced with temperature in Nb-modified Pb(Zr,Sn,Ti)O3 antiferroelectric-ferroelectric ceramics is studied. Experimental results reveal that the phase transitions are accompanied with marked pyroelectric peaks, there exists the close relation between the type of phase transition and the shape of pyroelectric peak. Because of the variations of phase transition, various pyroelectric spectra result. The pyroelectric spectrum can display the polarization effect and some inferior phase transitions with temperature variations, such as antiferroelectric AFEA-AFEB or ferroelectric FEL-FEH transition, which are not detected by the conventional dielectric measurement.
