scholarly journals A novel interval analysis method to identify and reduce pure electric vehicle structure-borne noise

2020 ◽  
Vol 475 ◽  
pp. 115258 ◽  
Author(s):  
Hai B. Huang ◽  
Jiu H. Wu ◽  
Xiao R. Huang ◽  
Wei P. Ding ◽  
Ming L. Yang
2006 ◽  
Vol 03 (02) ◽  
pp. 229-244 ◽  
Author(s):  
Y. T. ZHOU ◽  
C. JIANG ◽  
X. HAN

In this paper, the interval analysis method is introduced to calculate the bounds of the structural displacement responses with small uncertain levels' parameters. This method is based on the first-order Taylor expansion and finite element method. The uncertain parameters are treated as the intervals, not necessary to know their probabilistic distributions. Through dividing the intervals of the uncertain parameters into several subintervals and applying the interval analysis to each subinterval combination, a subinterval analysis method is then suggested to deal with the structures with large uncertain levels' parameters. However, the second-order truncation error of the Taylor expansion and the linear approximation of the second derivatives with respect to the uncertain parameters, two error estimation methods are given to calculate the maximum errors of the interval analysis and subinterval analysis methods, respectively. A plane truss structure is investigated to demonstrate the efficiency of the presented method.


2006 ◽  
Vol 324-325 ◽  
pp. 971-974 ◽  
Author(s):  
Chang Hong Liu ◽  
Hu Huang

With the concepts of the confidence interval, a random parameter can be transformed into an interval number in the mesco ductile fracture. Hence analyses of the random isolated void model can be used in the interval analysis method. Based on the macro- and mesco-experimental results of four steels, 30CrMnSiA, 40CrNiMoA, No.45 and No.20, the probabilistic fracture characteristics of the four steels are given. Finally the interval isolated void models in the four steels are discussed.


Author(s):  
Xin Song ◽  
Guannan Zheng ◽  
Guowei Yang

Abstract Uncertainties will make aircraft deviate from the designed condition, resulting in the decrease in aerodynamic performance and even destruction. This paper presents a fast nonlinear interval analysis method considering geometric uncertainties. DFFD method is used to parameterize the airfoil shape, and the Kriging model for aerodynamic force and uncertainty variables is optimized by PSO algorithm to find the upper and lower bounds of the objective interval. The effects of geometric uncertainties on NACA0012 airfoil are analyzed using the above method. And then, a robust optimization design method is established based on the interval analysis method. FFD method is used to produce the deterministic design variables and the order relation of interval number is employed to transform the uncertain optimization to deterministic multi-objective optimization which is solved by MOPSO based on Pareto entropy. The robust optimization design is implemented for the symmetrical airfoil with the drag objective under geometric uncertainties and thickness constraint, and the results are compared with the deterministic optimization to validate the effectiveness of the developed method.


Author(s):  
Jie Hong ◽  
ZheFu Yang ◽  
YaoYu Ni ◽  
YanHong Ma

Abstract Uncertainties in the input parameters are inevitable in any design process. Along with the demands for higher rotational speed and higher efficiency of rotating machinery, parameter uncertainties (e.g. support stiffness, the effective bending stiffness of connecting structures) resulted from the increasing load on rotor systems lead to significant scatter of its dynamic performance. These parameters are “uncertain but bounded” which means the distributions are unknown, but the intervals are always got easier. This paper presents a method to robustly optimize the dynamic performance of flexible rotor systems taking into account parameter uncertainties via interval analysis method. Interval analysis methods for modal properties and dynamic response behavior of rotor systems are developed with the interval variables introduced into the equation of motion. The aim of the robust design method is to optimize the critical speed margins and dynamic load on bearings, in the meanwhile, minimizing the variability of the objective items by the means of reducing their sensitivity to parameter uncertainties. A numerical example is presented, results show that, for the high-speed flexible rotor systems, the optimal choices of design variables could reduce of sensitivity to rotor parameter uncertainties, thus optimizing the variability of dynamic performance, which has important practical significance in engineering.


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