CAJ | 학술논문

基于随机振动理论,推导了车身结构随机振动响应谱的计算公式;采用Goodman曲线进行交变载荷的等损伤转换,建立了应力幅和平均应力之间的关系式;以材料的疲劳极限作为疲劳抗力指标,将残余应力等效为平均应力,以研究成形因素对疲劳性能的影响;以某汽车尾端横梁为例,采用基于有限元分析结果的疲劳分析法,考虑冲压成形因素的影响,进行了车身结构的动态应力计算、疲劳寿命预测和改进设计.结果表明,所预测的疲劳性能与整车道路试验结果吻合.
기우수궤진동이론,추도료차신결구수궤진동향응보적계산공식;채용Goodman곡선진행교변재하적등손상전환,건립료응력폭화평균응력지간적관계식;이재료적피로겁한작위피로항력지표,장잔여응력등효위평균응력,이연구성형인소대피로성능적영향;이모기차미단횡량위례,채용기우유한원분석결과적피로분석법,고필충압성형인소적영향,진행료차신결구적동태응력계산、피로수명예측화개진설계.결과표명,소예측적피로성능여정차도로시험결과문합.
Based on random vibration theory, the formulas for the random vibration response spectra of au-to-body structure are deduced. The alternative loading is converted to the loading with equivalent damage by using Goodman curve, and a relationship between stress amplitude and mean stress is established. Taking the fatigue limit of materials as the indicator of fatigue resistance, the residual stress is equivalent to mean stress for studying the effects of forming factors on fatigue performance. With the cross member at tail end of vehicle taken as an example, the dynamic stress calculation, fatigue life prediction and modification design of auto-body structure are performed by adopting fatigue analysis method based on the results of FEA for considering the effects of forming factors. The results show that the fatigue performance predicted well agrees with the results of vehicle road test.