Large Tension Stretching Machine Stretching Process And Belt Protection Research

Aluminum alloy thick plate is an important material for the aviation, aerospace, large heavy equipment manufacture industry. For the aluminum alloy plate, there are a lot of residual stresses after quenching. Mechanical properties distribution along the thickness is uneven, which will induce a lager machining size effect in follow-up processing. Pre-stretching process is an effective method to eliminate the quenching residual stresses. Pre-stretching process is quenched aluminum alloy plate, the tensile machine to trace pre-stretch (1%~3% deformation). After stretching the residual stress along the width is counteracted partly or even totally.During stretching process, if there are initial defects in alloy plate such as stress concentration or microcrack et al, alloy plate may be fractured ,when the stress in alloy plate exceed the permissible stress. As soon as the alloy is fractured, large impact force will be enforced on the jaw parts. So in order to ensure pre-stretching machine safe operation, it is important to study the breaking protect system.Pre-stretching process of aluminum alloy plate is analyzed based on the FEM software DEFORM. Stress and stain distribution can be obtained through the simulation. From the simulation results, we can see that stress produced by pre-stretching process can partly counteract the residual stress during the quenching process, when the pre-stretching deformation is 1%~3%. Additionally, it provides a guide for cutting area after pre-stretching. All this is of great significance for production.At the moment of breaking, clamping jaw parts is simplified reasonably, including parts geometry and the surroundings constrains. Movement model and mathematical model are established for clamping jaw parts. Simulations model corresponding to the motion model is proposed in MatLab. Movement procedure and parameter (displacement, velocity, acceleration) are studied in detail. In addition, mechanical model for the clamping parts is established, and dynamic response is analyzed after tensile fracture. Mechanical model for jaw is constructed in the finite element software, and stress and strain distribution is simulated. Buffer capacity for the buffer tank were calculated, the maximum force and pressure of the cylinder can be received. All this provides an important theoretical basis for the equipment.