近日,固體力學(xué)期刊Journal of the Mechanics and Physics of Solids(JMPS)以“A rate-dependent phase-field model for dynamic shear band formation in strength-like and toughness-like modes”為題報(bào)道了北理工方岱寧院士、陳浩森、曾慶磊團(tuán)隊(duì)在固體動(dòng)態(tài)失效領(lǐng)域的最新進(jìn)展。
相場法在模擬裂紋擴(kuò)展問題中已經(jīng)得到了廣泛應(yīng)用,近年來大家比較關(guān)注相場法能否準(zhǔn)確模擬裂紋萌生過程。動(dòng)態(tài)剪切帶(或者絕熱剪切帶)是金屬和合金材料在沖擊載荷下的重要失效模式,它們的萌生過程在文獻(xiàn)中一般被假設(shè)為兩類問題:類強(qiáng)度和類韌性,如圖1所示。本文將這兩類問題進(jìn)一步分為類強(qiáng)度、大范圍屈服和小范圍屈服三種模式,在熱力學(xué)一致框架下提出了基于能量準(zhǔn)則的率相關(guān)相場模型,可以準(zhǔn)確模擬各種動(dòng)態(tài)失效模式的萌生和演化過程。文章首先研究了力熱耦合失效問題中相場法特征長度的物理意義,結(jié)果表明率效應(yīng)或者溫度效應(yīng)顯著時(shí)特征長度的選擇會(huì)影響能量耗散過程,這一點(diǎn)與靜態(tài)問題相場模型明顯不同。接著對不同模式的剪切帶形成過程進(jìn)行了仿真,基于能量準(zhǔn)則的相場法可以很好地再現(xiàn)剪切帶萌生的應(yīng)變準(zhǔn)則或者應(yīng)力準(zhǔn)則,如圖2所示,并且不同失效模式的產(chǎn)生可以由剪切過程區(qū)的大小判定。最后,通過對文獻(xiàn)中不同幾何試樣、不同材料和加載方式的動(dòng)態(tài)剪切試驗(yàn)的模擬對比(圖3),證明了在統(tǒng)一的相場法框架下模擬各種動(dòng)態(tài)剪切失效模式的可行性。
圖1. 動(dòng)態(tài)剪切帶的類強(qiáng)度和類韌性模型
圖2. 相場法模擬的臨界剪切應(yīng)變和應(yīng)力與理論解的對比(LSY:大范圍屈服;SSY:小范圍屈服)
圖3. 相場法模擬結(jié)果與Kalthoff沖擊實(shí)驗(yàn)文獻(xiàn)結(jié)果對比
Q. Zeng, T. Wang, S. Zhu, H.-S. Chen, D. Fang. A rate-dependent phase-field model for dynamic shear band formation in strength-like and toughness-like modes. J. Mech. Phys. Solids, 2022, 164, 104914. DOI: 10.1016/j.jmps.2022.104914
https://www.sciencedirect.com/science/article/pii/S0022509622001156
2014以來,動(dòng)態(tài)失效固體力學(xué)小組(DFM)經(jīng)過近三年攻關(guān),自主研制國內(nèi)首臺(tái)線陣式高速紅外測溫儀器,并于19年開始攻關(guān)面陣式高速測溫儀器。目前已搭建了世界領(lǐng)先的動(dòng)態(tài)加載/高速光學(xué)(7M)/高速紅外(面陣初步)同步實(shí)驗(yàn)平臺(tái),深入開展動(dòng)態(tài)失效固體力熱耦合失效行為研究,在PRL(2019)、JMPS(2019,2020,2022)、MM(2019)等發(fā)表了系列工作。該工作得到了國家自然科學(xué)基金(11922202, 12002050,11802029)的支持。歡迎碩博士同學(xué)、博士后的加入,歡迎理論、仿真和材料研究團(tuán)隊(duì)的深入合作。
近期系列工作:
[1] Yazhou Guo, Qichao Ruan, Shengxin Zhu, Q. Wei, Haosen Chen, Jianan Lu, Bo Hu, Xihui Wu, Yulong Li, and Daining Fang. "Temperature rise associated with adiabatic shear band: causality clarified." Physical Review Letters 122, 1 (2019): 015503.
[2] Yazhou Guo, Qichao Ruan, Shengxin Zhu, Q. Wei, Jianan Lu, Bo Hu, Xihui Wu, and Yulong Li. "Dynamic failure of titanium: Temperature rise and adiabatic shear band formation." Journal of the Mechanics and Physics of Solids 135 (2020): 103811.
[3] Qinglei Zeng, Tao Wang, Shengxin Zhu, Haosen Chen, and Daining Fang. "A rate-dependent phase-field model for dynamic shear band formation in strength-like and toughness-like modes." Journal of the Mechanics and Physics of Solids (2022): 104914.
[4] Qinglei Zeng, Andrew L. Tonge, and K. T. Ramesh. "A multi-mechanism constitutive model for the dynamic failure of quasi-brittle materials. Part I: Amorphization as a failure mode." Journal of the Mechanics and Physics of Solids 130 (2019): 370-392.
[5] Qinglei Zeng, Andrew L. Tonge, and K. T. Ramesh. "A multi-mechanism constitutive model for the dynamic failure of quasi-brittle materials. Part II: Integrative model." Journal of the Mechanics and Physics of Solids 131 (2019): 20-42.
[6] Shengxin Zhu, Yazhou Guo, Haosen Chen, Yulong Li, and Daining Fang. "Formation of adiabatic shear band within Ti–6Al–4V: Effects of stress state." Mechanics of Materials 137 (2019): 103102.
[7] Shengxin Zhu, Yazhou Guo, Qichao Ruan, Haosen Chen, Yulong Li, and Daining Fang. "Formation of adiabatic shear band within Ti-6Al-4V: An in-situ study with high-speed photography and temperature measurement." International Journal of Mechanical Sciences 171 (2020): 105401.
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