Drying Tobacco Mechanical Properties Analysis

Based on the shell theory and commercial software platforms, the model of SH37Dtype cylinder manufactured by Qin Huangdao Tobacco Machinery Co. was established.This paper studied the phenomenon of cylinder cracks occurred during work. Found thecylinder stress concentration, analysed the causes of cracks, proposed amendments, andprovided a valuable reference for equipment modification.Because the shell thickness is far less than the diameter of cylinder internal weldingsteel plate, it belongs to the complicated thin shell structure. In this paper, based on theshell theory, established the structure model of SH37D type cylinder with shell elementson finite element software ABAQUS, analyzed the cylinder of the static characteristic andgot the stress state of the cylinder, did dynamic simulation and got the natural frequenciesand corresponding vibration modes and the state stress during exercise.In order to master the stress state of crack position on the cylinder, provide the basisfor the finite element simulation, with the technology of testing through strain gaugemeasured the strain around the threaded holes in the cylinder. Pasted0degree,45degreeand90degree direction strain gauges on the inner wall of the cylinder bolt. Stress statearound the threaded holes are presented, and compared with the calculated results,confirmed the correctness of the finite element simulation.The cylinder working temperature is90-100℃, the temperature can cause thermalstress shell, therefore, studied the cylinder’s strain field by thermo-mechanical couplenumerical simulation. The results show that thermal stress peak periodic appear alternatelyand the thermal stress exceeds the maximum allowable stress of cylinder body, caused thecrack damage on of cylinder screw thread hole, the simulation results in conformity withthe actual damage form of cylinder.According to the phenomenon of cracks on the cylinder, proposed improvementprograms which were thicken the whole cylinder body, thicken the damage location andchange the threaded holes’ position on the cylinder, demonstrated the feasibility of theoptions and provided some reference for the design of drying tobacco machine.