人下颌骨在不同应变率下的压缩强度

Compression strength of human mandible under different strain rate

目的 研究下颌骨在不同应变率下的生物力学性质 ,分析应变率和骨密度对压缩强度、弹性模量和破坏应变的影响 .方法 以 5具新鲜男性青年尸体的下颌骨为材料 ,对每具标本进行骨密度测定 ,然后制成标准试件在 INSTRON材料试验机上进行电子压缩 ,应变率分别为 0 .0 0 0 5 ,0 .0 0 5 ,0 .0 5 ,0 .5 s- 1 ,获得不同应变率下的应力 -应变曲线、下颌骨的极限强度、弹性模量以及破坏应变 .应用 Origin5 .0软件在 PC机上进行数据统计和分析 .结果 下颌骨在 0 .0 0 0 5 ,0 .0 0 5 ,0 .0 5 ,0 .5 s- 1的压缩应变率下的极限强度分别为 (10 3± 17) ,(12 0± 15 ) ,(134± 17)和 (15 0± 10 ) MPa;弹性模量分别为 (2 80 0± 189) ,(36 2 7± 34 5 ) ,(42 0 0± 835 )和 (5 12 0±936 ) MPa;破坏应变分别为 (0 .0 6 1± 0 .0 0 6 ) ,(0 .0 5 6±0 .0 0 9) ,(0 .0 5 0± 0 .0 0 9)和 (0 .0 45± 0 .0 10 ) .结论 下颌骨为粘弹性材料 ,其生物力学性质和应变率有密切关系 ,随着应变率数量级增加 ,压缩强度逐渐递增 ,而骨密度和压缩强度呈正相关 .

AIM To study the biomechanical behavior of human mandible under different compression strain rates and analyze the relationship between the strain rate and the strength, modulus and ultimate strain. METHODS Com pression tests for human fresh mandible at different strain rates ( ε =0.0005, 0.005, 0.05, 0.5 s -1 ) were performed on INSTRON to acquire the ultimate strength, breaking strain and modulus. The bone density of each individual mandible was measured. Origin 5.0 software was used to analyze all the data. RESULTS The ultimate strength was 103±17, 120±15, 134±17 and 150±10 N/mm 2, the breaking strain was 0.061±0.006, 0.056±0.009, 0.050±0.009 and 0.045±0.010, and the modulus was 2800±189, 3627±345, 4200±835 and 5120±936 N/mm 2 under the above four different strain rates. CONCLUSION The biomechanical behavior of human mandible is closely related with the strain rate and there exists a linear positive relationship between the ultimate strength and the bone density.