Method for estimating fatigue life of automobile structural component

Abstract

The invention discloses a method for estimating the fatigue life of an automobile structural member, which is characterized by comprising the following specific steps of (1) determining the yield limit sigma s and the fatigue limit sigma-1 of a part according to the material characteristics of the part, and measuring or estimating an S-N curve of the part; (2) calculating an optimal strengthening load Sg, an optimal strengthening effect betag and a strengthening load interval; (3) calculating the optimal strengthening effect beta R corresponding to the specific strengthening load and the strengthening effect beta R, n corresponding to the specific exercise times of the specific strengthening load; (4) carrying out cycle counting on the part load spectrum and grading the part load spectrum as Si, wherein the corresponding cycle number is ni; determining an enhanced load level Sq which corresponds to a cycle number nq; a damage load stage Sw corresponding to the number of cycles nw; (5) calculating the original fatigue life corresponding to each stage of load according to the S-N curve, and calculating the fatigue life after the optimal strengthening effect is obtained; (6) calculating the damage of a stage I and a stage II; and (7) when the fatigue failure phenomenon of the part occurs, calculating the total load block number, namely the fatigue life of the part.

Description

Technical field: [0001] The present invention relates to a vehicle technology, and more particularly to an invalid load threshold determination and a fatigue life estimate of automotive structural members. Background technique: [0002] The vehicle is affected by complex alternating load during operation, and fatigue damage is one of the main failure modes of the chassis structure. In the project, the fatigue life prediction and durability evaluation of the chassis structure were mainly used for methods of injury accumulation criteria. [0003] Materials or parts will be subject to different degrees of injury under external conditions, resulting in damage and its influencing factors have certain randomness. If the material mechanical properties caused by the recycling force, the method of deterioration is called fatigue damage. [0004] That is, when the part or material is higher than its fatigue limit, each load cycle causes a certain amount of damage to the part, and this dama...

AI Technical Summary

Problems solved by technology

[0008] Compared with the Miner criterion, it is necessary to obtain the k value of various parts under the corresponding loading conditions, but the k value is difficult to determine and depends on the fatigue test of similar loads, so it is difficult to obtain wide application

Images