Whole vehicle NVH calculation method based on modal super-unit

Abstract

The invention discloses a whole vehicle NVH calculation method based on a modal super-unit. The method comprises the following steps: constructing a whole vehicle model, dividing a TB model and a chassis model, respectively condensing the TB model and the chassis model into super-units, and connecting the modal super-units; collecting and obtaining boundary conditions, connection point freedom degree constraints, modal frequency ranges and whole vehicle acoustic calculation working conditions, and carrying out correlation matching with modal super units such as a chassis and a TB on the boundary conditions, the connection point freedom degree constraints, the modal frequency ranges and the whole vehicle acoustic calculation working conditions; adopting a modal super-unit reduction algorithm and combining boundary conditions, degree-of-freedom constraints, a modal frequency range and a whole vehicle acoustic calculation working condition to solve a whole vehicle calculation result and a vibration curve; performing comparative analysis on a whole vehicle calculation result, a vibration curve and a conventional result; and according to the whole vehicle calculation result and the vibration curve, extracting peak values and frequencies corresponding to the whole vehicle noise and the vibration curve. By the adoption of the scheme, the method has the advantages of being high in calculation and analysis efficiency, small in occupied space, high in result precision, simple and reliable in logic and the like, and has high practical value and popularization value in the technical field of vehicle NVH.

Description

technical field [0001] The invention relates to the technical field of vehicle NVH, in particular to a method for calculating the NVH of a vehicle based on modal superunits. Background technique [0002] NVH (Noise, Vibration, Harshness) is a comprehensive problem to measure the quality of automobile manufacturing, and it is the most direct feeling for automobile users. According to statistics, about 1 / 3 of the failure problems of the whole vehicle are related to the NVH problem of the car, and nearly 20% of the research and development costs of major car companies are spent on solving the NVH problem of the car. [0003] For vehicle-level NVH analysis, there are often millions of vehicle nodes and units. Under the premise of relatively short calculations and short project nodes, how to quickly and efficiently conduct vehicle NVH analysis. To propose more schemes in a limited time, it is particularly important to adopt the superelement method. [0004] At present, the NVH ...

AI Technical Summary

Problems solved by technology

[0005] In the prior art, in order to solve the NVH simulation of the whole vehicle, it is mainly analyzed through the conventional analysis model or the frequency response function super-unit method, and the frequency response function super-unit is mainly based on the method of calculating the NVH of the whole vehicle based on the frequency response function of the attachment point. It takes a relatively long time to create the superelement calculation model, especially when there are many attachment points, the transfer function will be very large, that is, the result file will be very large

And because the frequency response function method is used, it contains the complete matrix of the transfer function between the adjacent point and the interface, generally only supports the direct method to solve, and because the vehicle NVH model often includes millions of units, the calculation time is long , sometimes a calculation takes one day of calculation time, and only limited scheme calculation and optimization can be done in a limited time, which is difficult to meet the project node and performance development requirements, and also consumes a lot of manpower and material resources and other resources

Images