Research On Lightweight Of Carbon Fiber Reinforced Plastic Crossbeam Of Twist Beam

The twist beam of the rear suspension is a key component of the automobile chassis,and its lightweight design can help reduce the unsprung mass of the automobile,which will improve the fuel economy and the driving performance of the automobile.Considering that carbon fiber reinforced plastic have excellent mechanical properties and good designability,this paper applies it to the structure of crossbeam of automobile suspensions twist beam,and studies the lightweight design method of carbon fiber reinforced plastic crossbeam of twist beam.The design and development of frame structural parts have important reference significance.First of all,on the basis of exploring the mechanical theory of carbon fiber reinforced plastic.The mechanical properties test samples are made by vacuum-assisted molding combined with the test standards.The tensile test,compression test and in-plane shear test are carried out.Arrange the measurement data and calculate the mechanical property parameters of the carbon fiber composite material.Secondly,the finite element model of the steel twist beam is established to determine the analysis conditions and boundary conditions,and the performance of the U-shaped steel beam is obtained by simulation.The thickness of the U-shaped carbon fiber reinforced plastic beam is determined based on the design theory of equal stiffness,the simulation results are compared and analyzed,combined with the geometric characteristics of the thin plate structure,the U-shaped section of the twist beam structure is changed to an S-shaped section to verify the improvement effect.Based on the design principles of composite materials,a multi-layer optimization method including free size optimization,size optimization and Ply sequence optimization is used to obtain the optimal layup plan for S-shaped carbon fiber reinforced plastic beams.Finally,on the basis of the aforementioned optimal layup scheme,the layup thickness and layup angle of carbon fiber reinforced plastic are used as design variables to construct an approximate model between design variables and structural performance indicators,combined with NSGA-II algorithm and Monte Carlo optimized the reliability of carbon fiber reinforced plastic crossbeam and determined a lightweight design plan.The results show that,compared with steel crossbeam,the carbon fiber reinforced plastic crossbeam with reliability optimization can meet the design requirements underthe premise of ensuring higher reliability,and achieve the goal of light weight.