摘要
为了判断杆件结构的有限元分析精度对节点转动刚度是否敏感,并据此调整杆件结构的离散方式,根据Zienkiewicz-Zhu后验误差估计理论,定义了正应力范数来衡量有限元的计算精度,推导了考虑节点刚度的梁单元节点力-位移公式,并以试算得到的梁/杆单元的两节点位移作为边界条件,根据半刚性节点位移-力的公式,给出了杆件需要采用梁单元、杆单元、梁+弹簧单元离散的节点刚度范围,然后通过试算确定杆件结构的合理离散方式。在ANSYS中用APDL语言实现以上算法,并以2个简单结构为例说明了该算法的流程并验证了它的正确性。
A method is derived to judge whether the calculation precision of the finite element model of bar element structures is senstive to the rotating stiffness of the joints so as to adjust its discrete method, based on the Zienkiewicz-Zhu error post-processing technique, a stress norm is defined to judge the calculation precision, and the equations beteween dispacements and forces are derived by considering the rotation stiffness of the joints. Taking the nodal displacements resulting from the trial calculations of the beam/truss element model as boundary condtions, this method gives the scopes of rotating stiffness suitable to be discreted by truss elements, beam elements, and beam-spring elements. A case study on an 32-1eged structures is conducted to illustrate the feasibility and validity of the method in ANSYS.
出处
《工程力学》
EI
CSCD
北大核心
2013年第10期19-27,共9页
Engineering Mechanics
基金
国家电网公司科技项目资助项目(GC-10-006)
