Research On The Effect Of Side Window Bonding System On The Performance Of Bus Body Structure

Many model simplifications are made when a finite element model of bus body structureare created at most time. For instance, distributing the weight of window glasses to bus bodyinstead of taking into account the effect of window glasses on bus body structure is a way tosimplify. The finite element model ignores the effect of window glass on strength, stiffnessand rollover safety. The result is conservative which meets the need of general engineeringrequirements and the model is smaller for shortening the time of calculating. However, theresult has ignored the contribution to lightweight bus body structure design.In this paper, the research is started with the finite element simulation of side windowsimplified mode which is applied to the bus structure inspecting the effect of side window onstatic and dynamic performance of bus body structure. The finite element models of static anddynamic analysis will be used in the analysis of the bus body.In the static analysis part, simplified model of side window for static strength and stiffnessanalysis is studied. In order to unify with the bus body model, build the window frame andadhesive model with beam element, the glass model with shell element. The modulus ofelasticity, Poisson’s ratio and sectional dimension of the beam element are unknownparameters of the adhesive. A check factor is acquired to connect test with finite elementmodel for window frame model without glass. This factor will be applied to the window framemodel with glass to determine the unknown parameters of the finite element model byexperiment. Finally, establish finite element model of window frame with two pieces of glass,and test the accuracy of the model, resulting in a simplified model for strength and stiffnessanalysis. This model will be used in the analysis of the bus body structure to compare the onewith glass and the one without glass in strength and stiffness analysis.Bus rollover crash ends up in a very short time with the glasses destroyed in differentways. In this paper, we only study on the condition that glasses are damaged under impactloading. Tempered glass is a kind of brittle material which is difficult to observe its damage process and its failure stress is not easy to get through a test. There are researchers who havedemonstrated the strength limit of tempered glass is increasing as the strain rate increasing inprevious research. Therefore, the dynamic analysis of bus rollover crash is turned into aquasi-static research to study on the window glass destruction. Build the side window modelfor dynamic analysis. Paste tempered glass on the window frame. The thickness of glass, thewidth and thickness of the adhesives are consistent with the one for actual bus. In this model,the window frame is simulated with shell element and the adhesives and glass are simulatedwith solid element. The relevant parameters in the dynamic analysis model are the oneobtained in the static study. Find the maximum stress points in the finite element model as testpoints and past strain gates on these points to measure the ultimate strength of glass underexternal loads. Finally, this model will be used in the bus body segment structure. Compare thesegment structure with glasses and the segment structure without glasses in deformation of theoccupant space and the deformation energy of the main rods to examine the impact of sidewindow on bus rollover performance.The results found that the finite element model of side window has greater impact on thestrength, stiffness of the bus body, but less impact on the deformation of occupant space andthe deformation energy of most rods except the window pillar. It is necessary to build the finiteelement model of the side window strength and stiffness analysis. The finite element model ofthe side window makes some sense to the lightweight design of the bus body structure. Whenthe finite element model of side window is builded, the thickness and the size of relevant rodscan be decreased. However, the finite element model has less impact on the bus rolloverperformance which can be ignored when build the finite element model of the bus body forroller analysis.