mass单元是不需要设置材料。

ansys手册中有明确的描述

节点数：1

自由度：

UX, UY, UZ, VX, VY, VZ, AX, AY, AZ

Note:  For explicit dynamic analyses, V(X, Y, Z) refers to nodal velocity, and A(X, Y, Z) refers to nodal acceleration. Although V(X, Y, Z) and A(X, Y, Z) appear as DOFs, they are not actually physical DOFs. However, these quantities are computed as DOF solutions and stored for postprocessing.

Real Constants

If KEYOPT(1) = 0:

只需输入质量

If KEYOPT(1) = 1:

输入转动惯量

IXX - Moment of inertia (must be > 0),

IXY - Moment of inertia,

IXZ - Moment of inertia,

IYY - Moment of inertia (must be > 0),

IYZ - Moment of inertia,

IZZ - Moment of inertia (must be > 0)

材料属性

None, but you must define realistic dummy material properties to make this element behave correctly. The dummy properties will not be used in any solution.

Surface Loads

None

Body Loads

None

Special Features

All nonlinear features allowed for an explicit dynamic analysis.

KEYOPT(1)

Rotary inertia option:

0 -- 

3-D mass without rotary inertia (default)

1 -- 

3-D rotary inertia (no mass)