一种新的含转角自由度的四节点杂交元

A New 4-Node Hybrid Element Including Drilling Degrees of Freedom

基于组合杂交变分原理,使用含转角自由度的位移插值和CH(0-1)元应力模式,得到CHD(0-1)单元。它既满足杂交方法所要求的inf-sup条件,又有较高的位移、应力精度;和普通的八节点二次单元相比计算花费少;对单元几何形状不敏感;能很好地模拟弯曲变形。数值试验结果支持了本文结论。

A new element （CHD（0-1）） is proposed in this paper based on combined hybrid variational principle, of which the displacements include drilling degrees of freedom and the CH （0-1） stress mode are used. The new element not only satisfies inf- sup condition but also achieves high accuracy of both displacements and stresses. Compared with 8-node quadrilateral element, the computational cost of CHD（0-1） is lower. Moreover, it is insensitive to mesh distortion as well as simulating bending problems accurately. The conclusion is supported by the numerical results.