在adams中导入几何模型，设置材料时总提示The resulting body is not a valid manifold solid. It does not have any mass.问题出在哪呀，求大神指导

在adams中导入几何模型，设置材料时总提示The resulting body is not a valid manifold solid. It does not have any mass.问题出在哪呀，求大神指导