Study On Tensile Deformation Behavior Of Steel/CFRP Composites

In recent years,with the rapid development of the automotive industry,fuel consumption gradually increased,increasing air pollution,in ensuring the safety and comfort of the car under the premise of lightweight body to become the pursuit of the goal.On the one hand,high-strength steel is gradually replacing the ordinary,low-carbon steel will become the mainstream of the automotive industry,because of its high strength and thickness advantages,mainly for the lightweight body structure.On the other hand,Carbon Fiber Reinforced Polymer(CFRP)is widely used in the automobile manufacturing industry because of its light weight,high strength and good design.The high strength steel plate and the carbon fiber prepreg are compounded into steel/CFRP components.The deformation behavior and forming performance of the steel/CFRP are studied,which plays a key role in enhancing the lightweight space of the automobile.In this paper,the steel/CFRP composites composed of steel plate and carbon fiber prepreg were used to study the effects of carbon fiber layer,tensile speed and temperature on the tensile behavior,shear failure angle and maximum load of the composites.The influence of the factors on the deformation behavior of the composites,and the reasonable design and process conditions are obtained.Through the systematic study on the tensile deformation behavior of Steel/CFRP composites,the following main conclusions are drawn:(1)The tensile process of steel/CFRP composites mainly includes elastic deformation stage,strengthening stage,stationary stage and necking stage.The elastic deformation stage and the strengthening stage show typical linear elastic deformation behavior and nonlinear strengthening effect.In the stationary phase showed a uniform extension of the deformation properties of carbon fiber prepreg fracture occurred,lost the carrying capacity,in the uniform extension of the steel plate to bear all the tensile load.(2)The influence of temperature on the shear instability angle and the maximumtensile load is the most important factor in the three factors of carbon fiber layer,tensile speed and temperature.When the number of carbon fiber layers is 5,the tensile speed is 80mm/min and the temperature is 120?,the shear instability angle is the smallest,which indicates that the steel/CFRP composites have strong forming ability.When the number of carbon fibers is 9,the tensile speed is 160mm/min and the temperature is 25 ?,the maximum tensile load is the largest,indicating that the steel/CFRP composites have the strongest ability to resist fracture damage.(3)The shear loss stability of the carbon fiber prepreg is much larger than that of the steel sheet in the presence of the same carbon fiber sheet.The presence of the steel sheet significantly reduces the forming ability of the carbon fiber prepreg;on the other hand However,the tensile behavior of steel/CFRP composites is similar to that of pure CFRP prepregs,but the maximum tensile load is much larger than that of pure CFRP prepregs,indicating that the presence of steel plates is significantly improved The tensile strength of steel/CFRP composites.(4)On the basis of analyzing the constitutive model of carbon fiber prepreg and steel plate,the steel/CFRP composites with carbon fiber layer,tensile speed and temperature were established by linear superposition and multiple linear regression analysis.Structure model.