Numerical study on heat stress prefabricating ideal crack at the bottom of V shaped notch in precision cropping

摘要

Three main parts of a new type of precision cropping system with variable frequency vibration and corresponding working principles are introduced. The finite element software, ANSYS, is applied to build the model of the slotted metal bar, and the coupling simulation between the temperature field and the stress field is performed. The crack cannot appear in the vicinity of V shaped notch under the condition of zero width of the adiabatic boundary and only occurs when the width of the adiabatic boundary is greater than or equal to that of V shaped notch. The water spraying time decreases as the water velocity increases under the condition of the same width of the adiabatic boundary and it increases as the width of the adiabatic boundary increases under the condition of the same water velocity. It is the best choice that, for obtaining the initial crack as quickly as possible, the width of adiabatic boundary is equal to the width of V shaped notch and the water velocity is even higher. Experimental results show that by prefabricating the ideal crack at the bottom of V shaped notch with the heat stress, the high-quality cross-section is not only kept, but also the cropping time is reduced remarkably compared with the cropping method without the action of the heat stress,