| The seal strip is an important component of the vehicle sealing system,the bonding performance of the seal strip has an important influence on the performance of vehicle sealing,sound insulation,noise reduction,dust proof and water proof.In the bonding assembly process of the vehicle skylight seal strip,the longitudinal compression load will increase the bonding performance of the seal strip,while the model used for the rubber and the pressure-sensitiveadhesive layer of the seal strip is nonlinear and viscoelastic constitutive model,and there are nonlinear behaviors in the process of applying longitudinal compression loading on the seal strip,which is the difficulty in the analysis of the seal strip rubber and the adhesive properties of the pressure-sensitive-adhesive layer.Based on the longitudinal compression bonding process of the vehicle skylight seal strips and the cohesive zone theory,an exponentially softening cohesive zone model ESCM was proposed.Through the combination of the simulation analysis and the bonding experiment,the research was carried out around thebonding performance of the vehicle skylight seal strip under longitudinal compression.The main research contents of this paper include:（1）The nonlinear analysis of the rubber parts of the vehicle seal strip was carried out,the constitutive models of the two rubber materials of the seal strip were selected,and the bonding mechanism,bonding process and failure mode of the pressure-sensitive-adhesive of the vehicle seal strip were analyzed,which laid a foundation for the subsequent simulation work and the bonding experiment of the seal strip.（2）Based on the cohesive zone theory,an exponentially softening cohesive zone model（ESCM）was established,which considered the stiffness of the pressure-sensitive-adhesive and the real failure displacement parameters of the adhesive layer in the bonding experiment.The ESCM model was used to conduct two-dimensional simulation analysis of the vehicle skylight seal strip’s bonding model in the finite element analysis software ABAQUS.The failure process of a two-dimensional hybrid tensile model was analyzed by using the material failure indicator scalar CSDMG.（3）The finite element analysis software was used to simulate the three-dimensional model of the straight seal strip and the 90° bending seal strip under longitudinal compression load.The obtained load-displacement curve and the stress distribution on the surface of the bonding matrix were used to investigate the improvement of the bonding performance of each model under different compression rates.The distribution of the pressure-sensitive-adhesive layer’sbonding properties at different positions in the 90° bending model was analyzed.（4）An experimental platform for adhesive performance of seal strip was built and relevant experimental schemes were designed.By preparing seal strips under different pretreatment conditions,normal tensile failure experiments,compaction force experiments and standing time experiments were carried out on the seal strips of vehicle skylights.According to the experimental data,the influence of different pretreatment conditions on the bonding performance was analyzed,which provides a best installation parameters for the vehicle skylight seal strip. |
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