可变幅值载荷下牛骨的损伤累积

Damage accumulation of bovine bone under variable amplitude loads.

作者信息

Campbell Abbey M, Cler Michelle L, Skurla Carolyn P, Kuehl Joseph J

机构信息

Baylor University, Mechanical Engineering Department, One Bear Places, Waco, TX 76798, United States.

出版信息

Bone Rep. 2016 Nov 11;5:320-332. doi: 10.1016/j.bonr.2016.11.001. eCollection 2016 Dec.

DOI:10.1016/j.bonr.2016.11.001

PMID:28580403

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC5440782/

Abstract

Stress fractures, a painful injury, are caused by excessive fatigue in bone. This study on damage accumulation in bone sought to determine if the Palmgren-Miner rule (PMR), a well-known linear damage accumulation hypothesis, is predictive of fatigue failure in bone. An electromagnetic shaker apparatus was constructed to conduct cyclic and variable amplitude tests on bovine bone specimens. Three distinct damage regimes were observed following fracture. Fractures due to a low cyclic amplitude loading appeared ductile ( 4000 μ), brittle due to high cyclic amplitude loading (> 9000 μ), and a combination of ductile and brittle from mid-range cyclic amplitude loading (6500 -6750 μ). Brittle and ductile fracture mechanisms were isolated and mixed, in a controlled way, into variable amplitude loading tests. PMR predictions of cycles to failure consistently over-predicted fatigue life when mixing isolated fracture mechanisms. However, PMR was not proven ineffective when used with a single damage mechanism.

摘要

应力性骨折是一种疼痛性损伤，由骨骼过度疲劳引起。这项关于骨骼损伤累积的研究旨在确定著名的线性损伤累积假说——帕尔姆格伦-迈纳法则（PMR）是否能预测骨骼的疲劳失效。构建了一个电磁振动台装置，对牛骨标本进行循环和变幅试验。骨折后观察到三种不同的损伤状态。低循环振幅载荷导致的骨折呈韧性（<4000 μ），高循环振幅载荷（>9000 μ）导致的骨折呈脆性，中等循环振幅载荷（6500 - 6750 μ）导致的骨折呈韧性和脆性的组合。脆性和韧性断裂机制以可控的方式分离并混合到变幅载荷试验中。在混合分离的断裂机制时，PMR对失效循环的预测始终高估了疲劳寿命。然而，当与单一损伤机制一起使用时，PMR并未被证明无效。