平面理性八节点曲边四边形有限元RCQ8

由于理性有限元用弹性力学的解插值并且在物理域内直接列式，因而等参元相比，具有物理意义明确和精度高的优点，本文采用最高至４次的平面弹性力学的多项式解对单元位移插值，推出了八节点曲边平面理性元ＲＣＱ８，若干算例表明，本单元可以避免剪切自锁和体积自锁，具有很高的精度和效率以及数值稳定性。

8-Node curve quadrilateral rational finite element

As the rational finite element interpolates with the soultions of elasticity and formulates directly in the physical domain, it has superiority over the isoparametric finite element in clear physical meaning and accuracy. In the paper, up to 4 power of polynomial solutions of plane elasticity are used to interpolate the element dispacement and the 8\|node curve quadrilateral rational finite element RCQ8 is derived. Examples show that, it can avoid shear locking and volume locking, and has high accuracy, high efficiency and good stability.