jacq3d purpose

[__Jules_]

Hello,

I am having a detailed look in at the shell element you have implemented in FEAPpv. From my understanding it is a QUAD4 Element for the membrane part and a modified DKQ Element for the bending part. The modification is deep curvature, drilling DoF, flat to warped configuration. I was able to find the specific source code area and literature for the element warpage (ref. Taylor) and drilling DoF. Still I do not understand the function of the subroutine jacq3d. Unfortunately there is also no hint to any literature but I realised building my own element that this part plays a crucial role in the twisted beam example (warpage important). Maybe someone can provide some help or literature. Thank you in advance.

[Prof. R.L. Taylor]

This is the strain-displacment matrix for the DKQ.  It was coded many, many years ago based on:

@article{batoz82a,
author    = {J.L. Batoz and M.B. Tahar},
title     = {Evaluation of a new quadrilateral thin plate bending element},
journal   = ijnme,
volume    = {18},
year      = {1982},
pages     = {1655--1677} }

[__Jules_]

thanks a lot for the fast answer