This paper focuses on an estimation of light weighting opportunities for the frame structure of com- mercial road vehicles. This estimation is based on simpli- fied static load cases which play a predominant role for ...This paper focuses on an estimation of light weighting opportunities for the frame structure of com- mercial road vehicles. This estimation is based on simpli- fied static load cases which play a predominant role for the dimensioning of a frame structure and therefore these simplifications are not putting the general validity of the conclusions into question. A comparison of different ma- terials under this scenario shows that light metals do not show any weight reduction advantage in comparison to steel while a material-independent topology optimization has more weight reduction potential for the frame structure than a simple change of materials. Considering the con- straints of part complexity which is directly linked with production and assembly cost, the ladder frame structure has become the current state of the art design. Thus the paper also puts a spotlight on basic rules of node design and vertical load induction in order to keep the weight of such a design as low as possible. Practical examples from manufacturers show that the weight of a commercial vehicle could be reduced by 10%, and main parts of the frame structure could be reduced by 30% using high strength steel in combination with innovative production methods like roll forming.展开更多
Engineering vehicles are widely used under various harsh working conditions.For many components in them,service loadings they suffered are usually random and nonstationary due to their remarkable characteristic called...Engineering vehicles are widely used under various harsh working conditions.For many components in them,service loadings they suffered are usually random and nonstationary due to their remarkable characteristic called cyclic operation.To deal with that,section method can be applied.However,this method will neglect those transition cycles caused by switching load section,which can contribute a lot to fatigue.In order to consider those transition cycles,this paper applied the model called“Switching Markov Chain of Turning Points”(SMCTP).Then the expected rain-flow matrix is compared with the overall rain-flow matrix conducted by section method.The comparison result shows that SMCTP can perform well in processing nonstationary loadings.As a result,the Switching Markov Chain method(SMC)was proved to be effective in stochastically characterizing the nonstationary switching loadings of engineering vehicles.展开更多
文摘This paper focuses on an estimation of light weighting opportunities for the frame structure of com- mercial road vehicles. This estimation is based on simpli- fied static load cases which play a predominant role for the dimensioning of a frame structure and therefore these simplifications are not putting the general validity of the conclusions into question. A comparison of different ma- terials under this scenario shows that light metals do not show any weight reduction advantage in comparison to steel while a material-independent topology optimization has more weight reduction potential for the frame structure than a simple change of materials. Considering the con- straints of part complexity which is directly linked with production and assembly cost, the ladder frame structure has become the current state of the art design. Thus the paper also puts a spotlight on basic rules of node design and vertical load induction in order to keep the weight of such a design as low as possible. Practical examples from manufacturers show that the weight of a commercial vehicle could be reduced by 10%, and main parts of the frame structure could be reduced by 30% using high strength steel in combination with innovative production methods like roll forming.
基金National Natural Science Foundation of China(Grant No.51375202)National Natural science fund project(Grant No.51265020)Jilin Province Science and Technology Development Project(No.20160101285JC).
文摘Engineering vehicles are widely used under various harsh working conditions.For many components in them,service loadings they suffered are usually random and nonstationary due to their remarkable characteristic called cyclic operation.To deal with that,section method can be applied.However,this method will neglect those transition cycles caused by switching load section,which can contribute a lot to fatigue.In order to consider those transition cycles,this paper applied the model called“Switching Markov Chain of Turning Points”(SMCTP).Then the expected rain-flow matrix is compared with the overall rain-flow matrix conducted by section method.The comparison result shows that SMCTP can perform well in processing nonstationary loadings.As a result,the Switching Markov Chain method(SMC)was proved to be effective in stochastically characterizing the nonstationary switching loadings of engineering vehicles.
