关于结构高频响应分析中有限元网格划分的细化标准

ON FINING STANDARD OF FEM MESHING USED IN HIGH FREQUENCY STRUCTURE RESPONSE ANALYSIS

本文以周边简支方板在随机面分布力作用下振动加速度响应分析为例 ,用MSC/NASTRAN有限元软件研究了 0 -10 0 0Hz和 0 -2 0 0 0Hz频率范围内结构模态数和振动加速度响应均方根值随单元大小的变化规律。与解析法结合验证了由波动理论导出的单元细化标准。作为补充提出了结构模态数的单元细化标准。用相同方法对简支圆筒壳体在随机外压作用下 10 0 0 -2 0 0 0Hz频率范围内的加速度响应做了研究 ,本文提出的单元细化标准进一步得到验证。

As an example,the vibration acceleration response of the simply supported square plate loaded by random pressure is analyzed.The relations hip between number of modes,RMS of acceleration response(within 0_1000Hz and 0_2000Hz frequency bands) and the element size is studied by using MSC/NASTRAN software.As a complement,the fining standard of FEM meshing based on the number of modes is presented.The acceleration response of simply supported cylindrical shell loaded by random external pressure(within 1000_2000Hz frequency band) is also studied by the same method and the fining standard of FEM meshing presented in the paper is further confirmed.