【求助】HM前处理【默认单位】和【设置密度必要性】的问题

fergus1987

①  请教HM软件前处理中的默认单位分别是什么？
（质量、密度、长度、力、压强、弹性模量等）网上关于这方面的答案较少



②  在作非线性动力学分析（例如螺纹的抗拉、抗扭强度）时  【密度】在前处理时有必要进行设置吗？
感觉密度跟此类分析没有太大关系？



接触HM时间不长  还望各位大大不吝赐教！

lopex

1) HM claims itself as a unit-less software. which means, as long as your units are consistent, it is okay. take this as reference:

http://www.dynasupport.com/howtos/general/consistent-units

but in reality, few people build up a model in HM. mostly, CAD models are created by other software and imported into HM. these models usually using mm as default unit.
in this case, you have your length unit fixed. so, just choose between mm-ton-s-N-MPa or mm-kg-s-Pa.

2)depending on what kind of analysis you running, like the examples you gave, density is not necessary. I am not familiar with all the solvers, but if some solver happened to force you define a density, then just give it any value.
it is simple physics issue, you can find it out by writing out the matrix equations, whichever matrix is not present in the equation is ignorable.

cqcsq

对于HM单位的问题，没有什么默认的单位，自己可以设定，只要统一就可以了。如图中所示，单位统一即可。

fergus1987

cqcsq 发表于 2013-7-23 14:38
对于HM单位的问题，没有什么默认的单位，自己可以设定，只要统一就可以了。如图中所示，单位统一即可。 ...

谢谢大大！
请问这个表格是HM帮助文档里的吗？
还是所有的CAE软件都适用？

我的第二个问题能麻烦您解答一下吗？谢谢！

fergus1987

lopex 发表于 2013-7-24 04:22
1) HM claims itself as a unit-less software. which means, as long as your units are consistent, it i ...

How professional you are! Thank you very much!