Research On Lightweight Design Of Forklift Truck Door Frame System

Lightweight design is an interdisciplinary and comprehensive project,which involves structure,material,craft and other subjects.Lightweight design of forklift truck door frame system is of great significance to improve the performance of forklift truck,reduce manufacturing costs,lower energy consuming and protect the environment.After theoretical analysis,finite element simulation and stress test are adopted in the stress analysis process.Take the vertical balance load condition asan example,first of all,the force model of door frame is built after force characteristics analysis and the strength and stiffness formula of pallet fork,upper beam of inner door frame and door frame column are established.Then,the stress and displacement of door frame system under different working conditions is simulated by using the finite element method.So the key stress positions can be confirmed.Finally,a stress testing platform is set up to test stress of the key positions.To contrast the resultsby applying the above three methods,a conclusion can be drawn that both the theoretical analysis and finite element method are of high accuracy.Thus they can be used as theoretical basis for lightweight design of door frame system.Based on the above results,the finite element method is used to form simulations of the strength,stiffness and modal characteristics of forklift truck door frame system after shape optimization.And then two lightweight design methods,size optimization and strengthequivalent,are carried out in the lightweight design process.Firstly,the MATLAB optimization toolbox is used to optimize the designed size of pallet fork and door frame column.Secondly,existing materials HRB335 are replaced by material Q460 and then the thickness of the structure can be resigned based on formula h'= h(?).Then 3D models of the door frame system is built and simulated by the finite element method.By comparing the weight,strength,stiffness and modal characteristics of different door frame system designs,it can be concluded that under the same property requirements,a 18.9 percent weight of the door frame system can be reduced by replacing material HRB335 with Q460,and then optimizing the designed size of pallet fork and door frame column.Thus it is the best design among the above lightweight design methods.