Research On Roll Forming Technology And Unit Design Of 50-Type Spiral Steel Silo

The steel silo is a vertical storage container that stores flammable and explosive substances such as cement and other dust and alcohol.With the characteristics and sealing requirements of raw materials stored in related industries,the spiral steel silo has been widely used at domestic and abroad.In order to reduce the cost per unit capacity and increase the storage capacity,a larger diameter and higher strength steel silo is needed.While,nowadays,the domestic commonly used forming equipment is imported from abroad in the 1980 s,and it is impossible to manufacture larger-diameter steel silos.Based on this demand and practical value,this thesis puts forward through analyzing the forming process and forming principle of spiral steel silos and based on the roll forming theory.The 50-type spiral steel silo forming technology was designed,and the 50-type forming unit capable of processing galvanized sheets with a thickness of 3.0 mm to 5.0 mm was designed.The feasibility was verified by nonlinear dynamic simulation analysis and experimental prototype.The main research contents are as follows:(1)the forming process and operating principle of spiral steel silo was analyzed.Combined with the multi-roller cold bending forming theory and cold roll forming finite element technology theory,the spiral steel silo forming process was analyzed,and the forming angle distribution principle and the changes of curved voxels and straight voxels during the forming process were proposed.Based on the theory of elastoplastic mechanics,the mechanical analysis of the steel plate forming process was carried out,including the establishment of a mechanical model for the bending deformation of the strip,the mechanical analysis of the longitudinal deformation of the forming,and the mechanical analysis of the forming bending corners.(2)Completing the numerical calculation of the forming process based on the nonlinear dynamic finite element method.Based on the characteristics of the nonlinear explicit algorithm and the solution principle of time integration,the ANSYS preprocessor was used to establish a nonlinear finite element simulation model in two stages,and the ANSYS/LS-DYNA nonlinear analysis program was used to solve the problem.The best simulation rate for strip forming is to used this rate to calculate the two-stage finite element model step by step,and the distribution of the transverse stress and strain of the steel plate during the forming process,and the longitudinal stress and strain change with the pass were analyzed.(3)System design of the forming units.Combined the forming bending characteristics and the requirements of steel plate elongation control,the structural scheme of the forming unit was designed.Then the design and calculation of the transmission main shaft,the mechanical model of the shaft was constructed,the stiffness and strength were calculated,and the strength of the shaft was checked to meet the requirements by selecting dangerous points.The negative displacement gears designed in this paper are used to calculate the contact fatigue strength and bending fatigue strength using Hertz theory,and the simulation analysis is carried out using transient dynamics to verify that the numerical calculation results and Hertz theory calculation results meet the strength requirements.(4)Completed the experimental research of the forming units and analysis of the influencing factors of the forming.Through the principle experiment prototype design experiment plan,through the load data processing and collection system,the parameters of forming strip with different thickness are collected.By sampling the crimping ribs,the effect complies with the crimping standard of the spiral steel silo,which verifies the rationality of the forming sizes design in this thesis.Combining the linear relationship between force load and current,the correlation changes of molding load in each station are analyzed,and the dynamic simulation results of the molding process are compared to verify the correctness of the simulation results.Finally,the problems of data curve history and actual forming are discussed,and the forming angle increment is the main forming influencing factor,and the forming angle distribution needs to be further optimized.