Plate And Shell Structure Life Of Heavy Duty Crane Evaluation Analysis And Anti-fatigue Welding Research

A crane of the heavy class is a type of heavy machinery equipment for lifting and handling heavy goods,lifting liquid ladle is usually more than 100 tons.It is one of the key equipment in steelmaking equipment,used to lift molten iron and molten steel to different station areas.Such cranes are usually designed to work for long periods of time in high temperatures and harsh environments containing harmful gases.They often have to withstand extremely high temperatures,wheel pressure,and even corrosion and wear.Life expectancy evaluation has become an important aspect for enterprises.In view of this situation,the finite element method is used to study the dangerous parts of the bridge,and it is concluded that the reason for the crack is the shear of the weld,the damage of the structure and the defects of the design structure.Based on this,the welding temperature field is further set and the welding process is optimized.Based on the actual structure of heavy crane,a three-dimensional model of overall bridge structure is established.Crosswise comparison of stress and strain conditions under various working conditions is made,and the statics results are then compared to the actual working conditions,the maximum dangerous section and deflection conditions were obtained,thereby confirming the accuracy of the model’s construction.Integrating several kinds of software,the M integral method was employed to assess the initial and expansion stress intensity factors of cracks under three different working conditions,as well as to calculate their growth and fatigue life.The direction of the crack was then determined by analyzing the curve’s trend,and the weld’s crack was simulated.An examination of the correlation between the length of crack expansion and the number of load cycles was conducted to evaluate the safety margin and the crane’s life expectancy.In the actual manufacturing process of the crane,there will be many factors affecting the structural life.The law of welding deformation must be mastered by the structure of a welding temperature field simulation,based on the performance data for welding process optimization design,to minimize the impact of the process and strict control.This is due to the fact that the size of the deformation after welding not only impacts the precision and look of the structure,but also may diminish its bearing capacity.It has certain engineering significance.