Optimization Of Six-Hinged Linkage And Lightweight Design Of Boom For Mobile Elevating Work Platforms

Compared with the traditional aerial work equipment,such as scaffold,the mobile elevated work platform(hereinafter referred to as MEWP)features flexible movement,convenient height adjustment,increased operator efficiency,great application for compact construction sites,and low noise bringing non-adverse effect on urban daily life.However,if the lifting speed of the MEWP is too fast,the operator’s comfort will be affected.This paper described the optimization of the position of the six hinge points of the linkage to reduce the maximum acceleration of a certain MEWP,especially the telescopic boom lifts,then introduced the weight reduction of each boom section to reduce the weight of the boom system.The motion simulation software was used to parametrically model the boom system of the telescopic boom lifts.The coordinate positions of the six hinge points of the link structure were used as optimization variables,and the maximum acceleration of the boom lifts was used as the optimization target.After optimization,the maximum acceleration of the boom lifts was reduced by 87.13%.After the verification and optimization,the strength of the pin at the six hinge points meets the design requirements.The Hypermesh software was used to divide the finite element mesh of the boom system after optimization of the hinge point,and the Optistruct module was used to solve the finite element.For different working conditions,the stress distribution of the jib,the main boom and the linkage were obtained.The maximum stress value of each component under the most dangerous working condition and the vertical deflection of the whole machine were less than the maximum allowable value.After that,the optimization module was used to reduce the thickness of each boom section.The total weight of each boom section was reduced by 11.91% after optimization.For the optimized and lightweight telescopic boom lifts,calculated the stability of the unit on the 3.5 ° slope under the four working conditions of forward walking with boom fully lifted,forward walking with boom fully extended,forward tilt with boom fully extended,and backward tilt with boom fully retracted.Using motion simulation software,found the center of gravity coordinates of each component of the telescopic boom lifts at various angles,calculated the reaction force of the tire under four dangerous conditions,and analyzed the stability of the lifts on the slope of 3.5 ° afterhinge point optimization and weight reduction.Finally,the optimized and lightweight prototype was used to test the relationship between the acceleration of the boom lifting and the angle of the boom to verify the optimization effect of the maximum acceleration,to conduct stress test of dangerous points of each component of the boom system to verify the strength simulation results,deflection test for stiffness simulation verification,and stability test on slope of 3.5°to verify the calculation results of the slope stability of the whole machine in each case.The research results have a good research value to reduce the maximum acceleration and the weight reduction of the boom of the this type MEWP.