本文選題：超聲疲勞 + 超高周疲勞�。� 參考：《機(jī)械工程學(xué)報(bào)》2016年04期

【摘要】：在高頻循環(huán)載荷作用下,材料疲勞裂紋的萌生與擴(kuò)展過(guò)程伴隨著明顯的溫度變化,該溫度變化反映材料內(nèi)部結(jié)構(gòu)的損傷特征。通過(guò)20 kHz的超聲疲勞試驗(yàn),研究一種碳錳鋼在超高周疲勞加載條件下的內(nèi)部疲勞裂紋萌生與擴(kuò)展過(guò)程中溫度的演化過(guò)程。通過(guò)對(duì)該材料在疲勞損傷過(guò)程中,內(nèi)部裂紋間的摩擦生熱機(jī)理分析,從微觀角度出發(fā),結(jié)合分形理論,建立內(nèi)部裂紋微觀結(jié)構(gòu)的摩擦模型,數(shù)值模擬超聲疲勞過(guò)程中材料內(nèi)部疲勞裂紋面間的摩擦生熱情況,并定量地計(jì)算該過(guò)程中由裂紋間摩擦所導(dǎo)致的溫度上升,將模擬結(jié)果與試驗(yàn)結(jié)果進(jìn)行比較。探究高頻疲勞載荷下微裂紋擴(kuò)展與摩擦生熱的關(guān)系,并結(jié)合超高周疲勞裂紋擴(kuò)展公式,建立超聲疲勞過(guò)程中的裂紋擴(kuò)展與裂紋面溫度演化關(guān)系的模型。
[Abstract]:Under high frequency cyclic loading, the initiation and propagation of fatigue cracks in the materials are accompanied by obvious temperature changes, which reflect the damage characteristics of the internal structures of the materials. The temperature evolution of internal fatigue crack initiation and propagation of a carbon-manganese steel under ultra-high cycle fatigue loading was studied by ultrasonic fatigue test at 20 kHz. Based on the analysis of friction heat generation mechanism between internal cracks in the process of fatigue damage, the friction model of internal crack microstructure is established from the microscopic point of view and the fractal theory. The friction heat generation between the fatigue crack surfaces in the material was simulated numerically, and the temperature rise caused by the friction between the cracks in the process was calculated quantitatively. The simulation results were compared with the experimental results. The relationship between microcrack growth and friction heat generation under high frequency fatigue loading is studied. A model of the relationship between crack growth and crack surface temperature evolution during ultrasonic fatigue is established by combining the ultra-high cycle fatigue crack propagation formula.
【作者單位】： 西北工業(yè)大學(xué)機(jī)電學(xué)院;
【基金】：自然科學(xué)基礎(chǔ)研究計(jì)劃資助項(xiàng)目(2015JM1007)
【分類號(hào)】：TG115.57
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本文編號(hào)：2031486