Effect of dynamic loading on the frictional response of bovine articular cartilage
Effect of dynamic loading on the frictional response of bovine articular cartilage
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DOI：
10.1016/j.jbiomech.2004.07.025
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发表时间：
2005-08-01
影响因子：
2.4
通讯作者：
Ateshian, GA
中科院分区：
文献类型：
--
作者：
Krishnan, R;Mariner, EN;Ateshian, GA
本研究的目的是检验以下假设：（1）循环压缩载荷下关节软骨的稳态摩擦系数明显小于静态载荷下的平衡摩擦系数，并且随着载荷频率的变化而减小； (2)在周期性压缩载荷下，稳态软骨间质液载荷支撑保持显着大于零，并且随着载荷频率的变化而增加。在新鲜的圆柱形塞（n = 12）上，在三个正弦加载频率（0.05、0.5 和 1 Hz）和静态加载下，进行牛肩软骨在盐水中相对于玻璃滑动的无侧限压缩试验；测量随时间变化的摩擦系数 mu(eff)。组织间液负荷支持也从理论上进行了预测。在静态负载下，mu(eff) 从最小值 (mu(min) = 0.005 +/- 0.003) 增加到平衡值 (mu(eq) = 0.153 +/- 0.032）。在循环压缩负载测试中，mu(eff) 同样从最小值（0.05、0.5 和 1 Hz 时 mu(min) = 0.004 +/- 10.002、0.003 +/- 0.001 和 0.003 +/- 0.001）上升，并达到在下限 (mu(Ib) = 0.092 +/- 之间振荡的稳态响应） 0.016、0.083 +/- 0.019 和 0.084 +/- 0.020）和上限（mu(ub) = 0.382 +/- 0.057、0.358 +/- 0.059 和 0.298 +/- 0.061）。对于所有频率，发现 mu(ub) > mu(eq) 且 mu(lb) < mu(eq) (p < 0.05)。在周期性压缩载荷下，发现间质液载荷支撑在静态载荷响应之上和之下振荡，在稳态条件下，在载荷周期的一部分中发生吸力。所有理论预测和大多数实验结果都表明对加载频率的敏感性很小。根据这些结果，这两个假设都被拒绝了。与静态负载相比，循环压缩负载并未发现可促进更低的摩擦系数或更高的间质液负载支持。 (c) 2004 Elsevier Ltd. 保留所有权利。
The objective of this study was to test the hypotheses that (1) the steady-state friction coefficient of articular cartilage is significantly smaller under cyclical compressive loading than the equilibrium friction coefficient under static loading, and decreases as a function of loading frequency; (2) the steady-state cartilage interstitial fluid load support remains significantly greater than zero under cyclical compressive loading and increases as a function of loading frequency. Unconfined compression tests with sliding of bovine shoulder cartilage against glass in saline were carried out on fresh cylindrical plugs (n = 12), under three sinusoidal loading frequencies (0.05, 0.5 and 1 Hz) and under static loading; the time-dependent friction coefficient mu(eff) was measured. The interstitial fluid load support was also predicted theoretically. Under static loading mu(eff) increased from a minimum value (mu(min) = 0.005 +/- 0.003) to an equilibrium value (mu(eq) = 0.153 +/- 0.032). In cyclical compressive loading tests mu(eff) similarly rose from a minimum value (mu(min) = 0.004 +/- 10.002, 0.003 +/- 0.001 and 0.003 +/- 0.001 at 0.05, 0.5 and 1 Hz) and reached a steady-state response oscillating between a lower-bound (mu(Ib) = 0.092 +/- 0.016, 0.083 +/- 0.019 and 0.084 +/- 0.020) and upper bound (mu(ub) = 0.382 +/- 0.057, 0.358 +/- 0.059, and 0.298 +/- 0.061). For all frequencies it was found that mu(ub) > mu(eq) and mu(lb) < mu(eq) (p < 0.05). Under cyclical compressive loading the interstitial fluid load support was found to oscillate above and below the static loading response, with suction occurring over a portion of the loading cycle at steady-state conditions. All theoretical predictions and most experimental results demonstrated little sensitivity to loading frequency. On the basis of these results, both hypotheses were rejected. Cyclical compressive loading is not found to promote lower frictional coefficients or higher interstitial fluid load support than static loading. (c) 2004 Elsevier Ltd. All rights reserved.