计算驾驶室结构模态时，蒙皮怎么和骨架相连

很有可能是你的边界条件有问题，你可以换成一个简单的边界条件试一下，也有可能是单元边界上有重复节点，你没有equivalent，这样相当于有间隙存在 ，或者有自由的节点，因为从你的刚度矩阵中的负的数字-3.17以及特征值-3.43可以看出，你可以检查下模型

就会出现这样错误 Warning for eigenvalue subcase 2:
- At some point in the process, an inconsistent inertial count
was found. This implies that some of the calculated frequencies
may be inaccurate, especially the duplicated frequencies.
To avoid this, specify both bounds and keep the bound away
from the currently calculated frequencies.
*** warning *** the rayleigh quotient
x'kx / x'mx for the 1-th eigenvector
does not match the computed eigenvalue
lambda ( 1): -3.43657732493052D-02
x' k x : -3.17497987461738D-02
x' m x : 9.99999999999997D-01
discrepancy : 2.61597450313135D-03