比较正常股骨头和股骨头坏死后股骨头应力松弛性质,为人工关节研究和髋关节置换术提供应力松弛参数.在日本岛津电子万能试验机上对正常与病态股骨头各8个试样进行应力松弛实验.模拟人体温在36.5℃的温度场下进行实验,以5%/s的应变增加速度对标本施加应变,设定时间为7 200 s,采集100个实验数据.采用三参数模型计算应力松弛方程.观察应力松弛曲线和7 200 s应力松弛量.股骨头在最初600 s变化较快,之后应力缓慢下降,正常组7 200 s应力松弛量为0.31 MPa,病态组7 200 s应力松弛量为0.22 MPa,病态组7 200 s应力松弛量显著低于正常组(P＜0.05).股骨头坏死后打乱了松质骨头骨小梁的正常排列,骨量丢失,从而对应力松弛特性造成影响.应力松弛数据可以定量地说明坏死股骨头应力松弛特性差.%To compare the nature of stress relaxation of normal femoral head and necrosis femoral head to provide the stress relaxation parameter for the artificial joint research and the hip replacement. The stress relaxation experiment was carried on the Daojin electron universal testing machines of Japan with respecticrely 8 specimens of normal femoral head and necrosis femoral head. The experiment was carried on in 36.5℃ simulating human body temperature,5％s strain rate of increased was imposed on the specimen strain, the hypothesis time as 7 200 s,100 empirical data were gathed. Three parameter model computation stress relaxation equation was used. The stress relaxation curve and stress relaxation quantity at 7 200 s were observed. The stock bone had rapid changes during the first 600 s, afterwards the stress decreased slowly,the stress relaxation quantity of the normal group at 7 200 s was 0.31 MPa, the stress relaxation quantity of the morbid state group at 7 200 s was 0.22 MPa, the stress relaxation quantity of the morbid state group at 7 200 s was obviously lower than the normal group ( P ＜ 0.05) .After stock bone necrosis disrupted the normal arrangement of trabecular bone,the bone quantity lost, thus had the influence on the counter stressrelaxation characteristic. The stress relaxation data may proves that stress relaxation characteristic of necrosis stock bone is bad.
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