人下颌骨在不同应变率下的拉伸强度

Tension strength of human mandible under different strain rate

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极限强度、弹性真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拉伸，应变率分别为0．0003、0．003、0．03、0．3s-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Oropn5．0软件在PC机上进行数据统计和分析。结果：下颌骨在0．0003、0．003、0．03、0．3s-1的拉伸应变率下的极限强度分别为61．24、66．88、74．55、81．11N／mm2，弹性模量分别为15．17×103、16．72×103、1852×103、21．67×103N／mm2，破坏应变分别为0．731％、0．666％、0．625％、0．593％。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的关系．随着应变车数量级的增加，极限强度是逐后递增的，而骨密度和极限强度呈正相关关系。

To study the biomechanicalcharacteristics of human mandible under differenttension strain rate and analyze the relationshipbetween the strain rate and the strength, modu-lus and ultimate strain. Methods: Bone density forof 5 fresh human mandiblae was measured andthen tension test was performed at differentstrain rates (e= 0. 0003、0. 003、0. 03、0. 3 s-1)byusing INSTRON to acqure the ultimate strength,breaking strain and modulus,The soft ware of O-rigin 5. 0 was used to analyze all data. Results:The ultimate strength were 61. 24、66. 88、74. 55、81. 11N/mm2, breaking strain were 0.731%, 0. 666 %, 0. 625 %, 0. 593% and moduluswere 15. 17×103, 16. 72×103, 18. 52×103, 21. 67×103N/mm2 respectively under above four dif-ferent strain rates. Couclusion: Human mandibleis sensitive to strain rate (loading speed) andthere may be a positive correlation between theultitnate strength and bone density.