【求助】deform模拟切削中如何设定密度

zjudhy

    密度与温度是密切相关的，如果工件材料的密度为7800kg/立方米，在deform的key文件中如何体现出来？
    谢谢！

1wjlin

I don't think that the simulation of Deform 3D takes the material density for account since the menu in "Material data requirements" don't include the material density. It maybe a good research area for academy.  
  
In key file, it set up the material density as 0 as listed below,
  
MATDEN       1                    0.0000000E+000
=============================

zjudhy

但是涉及到热的问题要设计比热，比热的单位（J/kg/℃）是与质量相关的，与质量相关就涉及到密度。所以我觉得每种材料的密度应该具体设定。

1wjlin

Your concept belongs to the Thermodynamics and you may check the Heat Transfer books.
  
If you check the menu on the title of "UNIT", Deform3D uses the following unit relative to the volume instead of mass,
  
                                                       SI unit               English unit
Heat Energy                                    N-mm                      Klb
Conductivity                                    N/sec/C                   BTU/sec/in/F
Heat Flux Rate                                 N/mm/sec               BTU/in2/sec
Heat Capacity                                  N/sec/mm2/C           BTU/in3/F
Lubricant Heat Transfer Coefficient     N/sec/mm/C             BTU/sec/in2/F
  
The specific heat function could be relative to the volume in the solid materials, if it was under the melt point.  I guess that to avoid the converting problem, therefore, Deform3D uses the heat function relative to the volume instead of weight. How about your opinion?

zjudhy

Reasonable!
Thanks!

jinchee

1wjlin wrote:
I don't think that the simulation of Deform 3D takes the material density for account since the menu in "Material data requirements" don't include the material density. It maybe a good research area for academy.  
  
In key file, it set up the material density as 0 as listed below,
  
MATDEN       1                    0.0000000E+000
=============================

  
deform 3d 的手冊沒看過,
但無法輸入密度值的確令人困擾,
  
除了比熱用 "單位體積" 外,
  
個人有一疑問,
以 transient dynamics 來說, 密度是需要的, 但 defom 3d  卻沒有密度, 是不是 deform 3d 是用 quasi-static ??  靜態問題若不考慮自重和慣性力, 當然不須密度值.
我猜 deform 3d 考慮的 "dynamic效應", 是在 stress-strain-rate curve .
因為有 "strain rate".
用靜態算法,收斂性當然比較好~
  
  

liflutter

同感