The micro-structural parameters such as reinforcement shape, size, distribution, volume fraction, property mismatch, aging condition, bonding strength, and whisker orientation can influence the fatigue life of discontinuous reinforced metal matrix composites (DRMMCs). The strengthening effect plays a vital role in predicting the fatigue behaviour of DRMMCs. The modified shear lag (MSL) and enhance dislocation density (EDD) are two main factors that describes the strength of DRMMCs. In the present work, fatigue crack growth life model based MSL and EDD strengthening mechanism has been developed by integrating fatigue damage deformation at the crack-tip under the total strain-controlled conditions. The closed form expression predicts the dependency of particle size, reinforcement volume fraction and reinforcement constraint of the matrix on the fatigue crack growth life. The model fitting with experimental data affirms the appropriateness of proposed fatigue crack growth life prediction model for DRMMCs.

中文翻译：

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微观结构参数对不连续增强金属基复合材料疲劳寿命的影响

微观结构参数，例如增强材料的形状，尺寸，分布，体积分数，性能失配，时效条件，粘结强度和晶须取向，会影响不连续增强金属基复合材料（DRMMC）的疲劳寿命。增强作用在预测DRMMC的疲劳行为中起着至关重要的作用。修正的剪切滞后（MSL）和增强的位错密度（EDD）是描述DRMMC强度的两个主要因素。在目前的工作中，通过在总应变控制条件下整合裂纹尖端的疲劳损伤变形，开发了基于MSL和EDD增强机制的疲劳裂纹扩展寿命模型。闭合形式的表达式可以预测颗粒大小的依赖性，基体的体积分数和基体的增强约束条件对疲劳裂纹扩展寿命的影响。与实验数据拟合的模型证实了所提出的针对DRMMC的疲劳裂纹扩展寿命预测模型的适当性。