Probabilistic Dynamic Errors in Internal Combustion Engines

本研究项目涉及受不连续强迫函数作用的机械系统公差分析的概率方法。采用频域/时域交替法求解动力方程。统计量是通过确定傅里叶系数对随机变量的偏导数来评估的，在本研究中，随机变量是连杆长度公差和销钉位置。这些是连杆长度公差、径向间隙和相关公差的设计变量的代表。在满足给定约束条件的情况下，求解了公差方差最大的非线性约束优化问题。本文的研究成果为内燃机等动态系统公差分配分析设计工具的开发提供了基础

This research project deals with probabilistic methods of tolerance analysis for mechanical systems subjected to discontinuity forcing functions. The dynamic equations are solved using the alternating frequency/time domain method. The statistics is evaluated by determining the partial derivatives of the Fourier coefficients with respect to the random variables which, in this research, are link length tolerances and pin locations. These are representative of design variables of link length tolerances, radial clearances and associated tolerances. A nonlinear constrained optimization problem is solved in order to maximize the variances of tolerances, while satisfying the specified constraints. The results of this research lead to the development of an analysis and design tool for tolerance allocation in a dynamic system such as an internal combustion engine.***//