前足部足底軟組織之組成律與自然頻率分析

Abstract

在得到前足部足底軟組織的應力、應變對時間的曲線後，我們找到一個有效的數學模型(組成律)來對此進行分析，在確立組成律的方程式之後，使用最佳化的方式來求出與實驗結果相符的組成律係數值，接者觀察線性組成律及非線性組成律在特定的應變輸入下所反應出來的應力曲線及能量散失的趨勢，最後假設一個軟組織的長塊狀模型，利用Hamilton’s principle推導其運動方程式，並對此模型做頻率分析，觀察組成律係數之改變對於振幅及頻率所造成的影響。

Based on the time histories of stress and strain of the sole under metatarsal heads during the loading and unloading process, we propose an appropriate, nonlinear, viscoelastic model that describes probably the constitutive law for that soft tissue. We use the technique of optimization to find the parameters in the equation of the constitutive law that fit best the experimental data. By varying the strain waveform, we can derive theoretically the explicit equation expressing the relation between the energy dissipation and the parameters of the constitutive law. Besides the stress and strain analysis, we have also done the vibration analysis of the sole’s soft tissue. We use Hamilton’s principle to derive the equations of vibration of the sole’s soft tissue. The effects of the parameters in constitutive law and the geometric size of the soft tissue on the frequency shift and amplitude change are studied.