水中諧響應求解時出現如下錯誤：

property sons of material 4 referenced by element 1 was set to 0 which cannot be negative or extremely small.

property sons of material 3 referenced by element 76801 was set to 0 which cannot be negative or extremely small.

property sons of material 5 referenced by element 204001 was set to 0 which cannot be negative or extremely small.

其中材料3、4、5分別為近場水，遠場水，邊界水；不知是材料設置的問題還是網格劃分的問題，還是什么其他問題？？求大神給小弟指教，謝謝！！！