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（鄭州大學(xué)力學(xué)與工程科學(xué)學(xué)院， 鄭州 450001）
［摘要］基于微觀機制的循環(huán)微孔擴展模型可以用來預(yù)測鋼材的超低周疲勞斷裂，但是該模型主要考慮應(yīng)力三軸度的影響，而忽略了Lode參數(shù)對鋼材超低周疲勞斷裂的影響。在循環(huán)微孔擴展模型（CVGM模型）的基礎(chǔ)上，提出了考慮Lode參數(shù)影響的斷裂模型（LCVGM模型）。采用Q235B鋼材設(shè)計并加工了一批可表征不同應(yīng)力狀態(tài)的試件，開展了試件的單調(diào)拉伸和超低周循環(huán)加載試驗。根據(jù)試驗和有限元計算結(jié)果，得到了Q235B鋼材的LCVGM模型參數(shù)。最后，利用考慮Lode參數(shù)影響的Q235B鋼材的LCVGM模型預(yù)測了平面應(yīng)變試件的超低周疲勞斷裂過程，預(yù)測結(jié)果與試驗結(jié)果的吻合很好，并且比CVGM模型的預(yù)測精度更高。
［關(guān)鍵詞］Q235B鋼材；超低周疲勞斷裂；Lode參數(shù)；循環(huán)微孔擴展模型
中圖分類號：TU391文獻標(biāo)識碼：A文章編號：1002-848X(2021)04-0124-07
Cyclic void growth model of Q235B steel considering influence of Lode parameter
ZHAO Wei, HUANG Xuewei, ZHAO Jun, GE Jianzhou
（School of Mechanics and Engineering Science, Zhengzhou University, Zhengzhou 450001, China）
Abstract:The cyclic void growth model based on the micro-mechanism can be used to predict the ultra-low cycle fatigue fracture of steel, but the model mainly considers the influence of stress triaxiality, and ignores the influence of Lode parameters on the ultra-low cycle fatigue fracture of steel. A fracture model considering the influence of Lode parameters was proposed based on the cyclic void growth model (CVGM model), which was namely as LCVGM model. A batch of test pieces that could characterize different stress states were designed and processed using Q235B steel, and monotonic tensile and ultra-low cycle loading tests of the test pieces were carried out. According to the test and finite element calculation results, the LCVGM model parameters of Q235B steel were obtained. Finally, the LCVGM model of Q235B steel considering the influence of Lode parameters was used to predict the ultra-low cycle fatigue fracture process of the plane strain specimen. The prediction results were in good agreement with the test results, and the prediction accuracy was higher than that of the CVGM model.
Keywords:Q235B steel;ultra-low cycle fatigue fracture;Lode parameter;cyclic void growth model
*國家重點研發(fā)計劃（2016YFE0125600），國家自然科學(xué)基金（51608487），教育部創(chuàng)新團隊發(fā)展計劃（IRT_16R67），河南省科技攻關(guān)項目（192102310221）。
作者簡介：趙威，碩士， Email：zhaow@gs.zzu.edu.cn；通信作者：黃學(xué)偉，博士，講師，Email：huangxw@zzu.edu.cn。
