Department;
of;
Mechanical;
Engineering,;
Academy;
of;
Armored;
Force;
Engineering,;
No.21,;
Du;
Jia;
Kan,;
Chang;
Xin;
Dian,;
Beijing;
100072,;
China;
School;
of;
Mechanical;
Engineering,;
Yonsei;
University,;
Seoul;
120-749,;
South;
Korea;
bi-FGM复合材料; 三级模型裂缝; 应力强度; 积分方程;