Romanowicz Paweł J, Smolarski Dariusz, Kozień Marek S
Department of Machine Design and Composite Structures, Faculty of Mechanical Engineering, Cracow University of Technology, ul. Warszawska 24, 31-155 Kraków, Poland.
Institute of Technology, State University of Applied Sciences in Nowy Sącz, ul. Staszica 1, 33-300 Nowy Sącz, Poland.
Materials (Basel). 2021 Dec 28;15(1):196. doi: 10.3390/ma15010196.
A new approach based on the direct spectral method for fatigue analysis of elements subjected to bimodal stress histories, including high compression effects, is proposed. A correction factor, taking into account the influence of the mean compressive stresses, is used in the proposed method. Equivalent amplitude is estimated, based on criteria proposed by Smith, Watson, and Tooper, and by Bergmann and Seeger. The method is presented with example of a thrust roller bearing. Two cases in which the rollers were subjected to constant force 206 N (where constant amplitude stresses occurred in the rollers) and cyclic force (where bimodal stresses with variable amplitudes occurred in the rollers) are studied. It is observed that multiaxial fatigue criteria (Crossland, Papadopoulos) do not include the influence of bimodal stresses and should not be used for such loading conditions. The proposed method includes both kinds of stress waveforms in the fatigue analysis and can be applied for the accurate identification of stress components and the determination of fatigue life. The damage rate calculated by the proposed approach for rollers subjected to a cyclic force (equivalent load equal to 151 N) was 0.86, which is in good agreement with the recommendations provided in the literature. The obtained accuracy of the proposed method is above 95%.
提出了一种基于直接谱方法的新方法，用于对承受双峰应力历史（包括高压缩效应）的元件进行疲劳分析。在所提出的方法中使用了一个考虑平均压缩应力影响的修正因子。基于史密斯、沃森和图珀以及伯格曼和西格提出的准则来估计等效幅值。以推力滚子轴承为例介绍了该方法。研究了两种情况，其中滚子承受恒定力206 N（滚子中出现恒定幅值应力）和循环力（滚子中出现幅值可变的双峰应力）。观察到多轴疲劳准则（克罗斯兰、帕帕多普洛斯）未考虑双峰应力的影响，不应在此类载荷条件下使用。所提出的方法在疲劳分析中包括了这两种应力波形，可用于准确识别应力分量和确定疲劳寿命。对于承受循环力（等效载荷等于151 N）的滚子，用所提出的方法计算出的损伤率为0.86，这与文献中的建议吻合良好。所提出方法的获得精度高于95%。
