对Volvo驾驶室翻车保护系统测试有限元模拟的影响因素分析

Abstract

The ability to protect the operator if a rollover of a construction equipment vehicle should take place is an essential requirement. In order to fulfil the necessities of this aspect, each cab constructed today is provided with a Rollover Protective Structure (ROPS).

The cabs developed by Volvo Construction Equipment undergo a ROPS-test. These tests are performed to ensure that the cab is able to uphold certain forces and consume certain energy levels without exceeding the restrictions in terms of displacements. As a part of the design process,Volvo uses simulations of these tests.

Comparisons made between tests and simulations have usually shown good agreements. This was not the case in a recent comparison of results. The objective of this thesis is to explain why the simulation of this test did not show satisfying agreement with the physical test.

By designing and constructing a welded component of standard beams and testing this as well as developing a finite element model of the component, an investigation of the influence of different parameters has been done.

The results from this thesis show that the major part of the divergence is due to non-correct material data. From yield tests and hardness measurements, material data has been obtained. These data show that the forming process, while manufacturing structural parts as well as welding these, strengthens the material with respect to the yield strength. Another major influence on the results comes from the modelling of welds in the FE-model.

With corrections for material data made in combination with a number of other changes of the model, results far better than the original are obtained.