关键词: 材料合成与加工工艺, 连杆, 裂解, 塑性区, 启裂点, 裂解质量

Abstract: The fracture splitting process of the connecting rod big end with the starting notches under static loading was numerically analyzed. The planar stress and strain states in the crack zones of the connecting rod were presented qualitatively by comparing the shape of the plastic zone at the crack tip of the connecting rod with an ideal plate, making it possible to analyze the fracture states on different areas. It was found that the plastic zone at the crack tip varies thicknesswise, and the fracture will start at the crack zone whoe planar strain state firstly reaches the deformation limit. The difference of the plastic zone at the crack tip leads to the scattering of the starting cracking points, crack spreading asynchronously and in different paths. All of these may result in the defects of the connecting rod splitting, such as the crack bifurcation unnormal crack joints, and the fracture disfigurements like the avulsion, corner collapse, step fracture surface, scrap inclusion, and dissilient exterior edge,etc.

Key words: material sythesis and processing technology, connecting rod, fracture splitting, plastic zone, crack start, fracture quality