摘要
为考虑汽缸盖不同位置力学性能差异对疲劳评估的影响,提出一种考虑汽缸盖力学性能分散性的疲劳评估方法。首先,在汽缸盖本体的顶板、底板、进排气道壁和立墙部位分别取样,进行拉伸试验并分析各部位的力学性能分散性。然后,测量汽缸盖各区域的微观组织结构特征,建立基于微观缺陷的拉伸性能预测模型。并利用拉伸性能与疲劳强度关系,建立疲劳极限预测模型。最后,基于多轴高周疲劳理论,结合热机耦合应力以及材料边界,提出汽缸盖疲劳强度分区评价方法。结果表明,建立的力学性能模型的预测误差约为2%,实现了对汽缸盖各区域力学性能的准确预测。与传统的疲劳评估方法相比,所提方法结合了工作载荷和材料分散性两个因素的影响,其评估的危险位置与试验开裂部位一致,因此可以更加准确地表征缸盖的疲劳性能。
In order to consider the influence of mechanical properties of different positions of cylinder head on fatigue assessment,a fatigue assessment method considering the dispersion of mechanical properties of cylinder head was proposed.Firstly,samples were taken from the top plate,bottom plate,intake and exhaust port walls and vertical walls of the cylinder head body,and tensile tests were carried out to analyze the dispersion of mechanical properties of each part.Then,the microstructure characteristics of each area of the cylinder head were measured,and a prediction model of tensile properties based on microscopic defects was established.A fatigue strength prediction model was established by using the relation between tensile properties and fatigue strength.Finally,based on the multi⁃axial high⁃cycle fatigue theory,combined with the coupled thermo⁃mechanical stress and material boundary,a zonal evaluation method for the fatigue strength of the cylinder head was proposed.The results show that the prediction error of the established mechanical performance model is about 2%,which can accurately predict the mechanical performance of each area of the cylinder head.Compared with the traditional fatigue assessment method,the proposed method combined the influence of two factors of working load and material dispersion,and the estimated dangerous position was consistent with the test cracking position,so it can more accurately characterize the fatigue performance of the cylinder head.
作者
吕振国
周海涛
周志革
景国玺
李书博
刘义朋
何晓东
李鹏
LÜZhenGuo;ZHOU HaiTao;ZHOU ZhiGe;JING GuoXi;LI ShuBo;LIU YiPeng;HE XiaoDong;LI Peng(School of Mechanical Engineering,Hebei University of Technology,Tianjin 300400,China;Tianjin Key laboratory of Power Transmission and Safety Technology for New Energy Vehicles,Tianjin 300400,China;China North Engine Research Institute(Tianjin),Tianjin 300400,China)
出处
《机械强度》
CAS
CSCD
北大核心
2024年第3期579-587,共9页
Journal of Mechanical Strength
基金
国防科技重点实验室基金项目(61422120301)资助。
关键词
铸铝汽缸盖
力学性能分散性
力学性能预测
疲劳强度
二次晶枝臂间距
Cast aluminum cylinder head
Dispersion of mechanical property
Mechanical property prediction
Fatigue strength
SDAS
