One or more diagonal terms of the modal covariance matrix (i.e., when mode i = mode j) is negative. The 1 sigma results may be incorrect as a result of the input PSD curve being improperly represented. Please review the results carefully.
如上，隨機(jī)振動仿真有這個警告，但是我不知道如何解決，請問有大神幫忙嗎~？