壳体的Simpson积分和Gauss积分，积分点怎么设置？

xiyurunwu

我用Abaqus 做复合材料，看到手册里说，Gauss积分在壳的表面没有积分点，而Simpson 却有，这怎么理解啊？
这是手册里的原话：
Using Simpson's rule

By default, Simpson's rule will be used for the shell sectionintegration. The default number of section points is five for a homogeneoussection and three in each layer for a composite section.

Simpson's integration rule should be used if results output on theshell surfaces or transverse shear stress at the interface between two layersof a composite shell is required and must be used for heat transfer and coupledtemperature-displacement shell elements.

Using Gauss quadrature

If you use Gauss quadrature for the shellsection integration, the default number of section points is three for a homogeneous section and two ineach layer for a composite section.

In Gauss quadrature there are no sectionpoints on the shell surfaces; therefore, Gauss quadrature should be used only in caseswhere results on the shell surfaces are not required.

Gauss quadrature cannot be used for heattransfer and coupled temperature-displacement shell elements.

没有看到，关于壳体的数值积分的资料啊?  为什么复合材料每层壳单元的Gauss积分，表面没有Gauss积分点啊？

D_eagle

这是由积分本身的特点决定的

mxlzhenzhu

对等参元，积分点是固定的。

gogouter

兄台去查一下数值分析就知道了。
gauss积分用最少的点得到2N-1阶精度，计算量下来了，代价就是俺们关心的节点恰恰不是积分点，有时候TMD误差还很大，后处理有时候外插很不靠谱。
shell厚度方向也一样的道理！