In ovx rats , not only bone mineral density ( bmd ) of lumbar vertebrae in vivo and vitro , but also bmd of femora ( except for r3 region ) and proximal metaphysis ( r1 region ) in vitro decreased obviously ( p < 0 . 01 ) ， whose bone loss rates of l5 and l6 were the highest and achieved 13 % ; the trabeculae of ovx rats were few ， fine , and discontinued and there were lacunae on the surface ; in ovx rats , both compressive strength of vertebral bodies and the mechanical properties of femora decreased ; the falling degree of the former was greater ; the maximal compressive power of lumbar vertebrae decreased with 33 . 32 % 结果显示：大鼠卵巢切除后，活体、离体腰椎以及股骨（除r3区） 、胫骨近端干骺端（ r1区）的离体骨密度显著下降（ p < 0 . 01 ） ，离体l5和l6的骨丢失率最大，达13 % ；骨小梁减少、变细，连接中断，骨小梁表面有吸收陷窝；腰椎压缩强度和股骨力学性能均下降，前者更明显，腰椎最大压缩力下降率达33 . 32 % 。
Therefore , interlayer toughened composites are the excellent candidate materials for primary structure of aircrafts . in this paper , composites modified with particle - interlayer were fabricated . based on the aims of improving compression strength after impact ( cai ) and evaluate damage resistance and damage tolerance , mode ii fracture toughness test and quasi - static indentation test ( qsi ) were conducted 本文采用层间颗粒增韧技术制备试验件，基于提高冲击后压缩强度( cai )和考察损伤阻抗、损伤容限的目的，试验测试了型层间断裂韧性g _ ( c ) 、准静压痕( qsi )试验的分层起始能量和接触力?凹坑深度关系。
The existing problems in toughened resin evaluation technology , particularly the disadvantage of the toughened resin identification method by cai , is pointed out based on the point of view of composite structure design . it is proposed to evaluate the toughness of composites by both damage resistance and damage tolerance . seven different toughness composites are investigated by impact and quasi - static indentation tests . based on experimental data analysis , the parameter that is most sensitive to the damage resistance is determined as the damage parameter . the parameter to evaluate the damage resistance and its measuring method are proposed 从复合材料结构设计的角度,指出了目前在韧性复合材料评定技术中存在的问题,特别是指出了用冲击后压缩强度值作为判别复合材料韧性的缺点,提出了应采用损伤阻抗和损伤容限共同评定复合材料韧性的观点.对7种不同韧性的复合材料进行了冲击与静压痕等试验,在对试验数据分析的基础上,确定了对损伤阻抗最敏感的损伤参数,提出了描述损伤阻抗的物理量和测试方法
