An incompatible displacement element and a hybrid stress element are developed to model the effective mechanical properties of three-dimensional(3-D) textile composites.

Based on a modified Hellinger/Rcissner veriational principle which includes the equivalent stressequivalent plastic strain and non-conforming displacement increments as independent variables,a quadri-lateral isoparametric hybrid stress element for the analysis of elastoplastic problem is proposed.

A new 5-nodes spesial hybrid stress element with free cylindrical surfaces has been developd based on the theory of Hellinger-Reissner.

It has the advantage of the generalized finite strip method and hybrid stress element.

This paper try to mix the finite strip method and hybrid stress element, and deduce a numerical and computer method which combines the advantages of the two methods -mixed hybrid finite strip method; analyze the intensity and stability of the orthotropic plate by this method; deduce the for.

Based on the complex potential method in the plane theory of elasticity of an anisotropic plate containing an elliptical inclusion,and using hybrid variational principle,a hybrid stress element with an arbitrary elliptical inclusion for anisotropic plates has been established,which assorts with the conformal finite element.

The complex potential method for an anisotropic plate containing an elliptical inclusion and a hybrid variational principle are used to establish a hybrid stress element which assorts with the conformal finite element.

Abandoning the uniaxial stress assumption,a continuum laminated beam model in terms of deflection induced by label-free biodetections is set up to study nanomechanical behaviors of a biodetector subjected to hybridization surface stresses and thermal loads.