基于ANSYS的PDC钻头钎焊裂纹应力场和应力强度因子分析

ANSYS-based analysis on stress field and stress intensity factor of brazing seam in PDC bits

金刚石复合片(PDC)钻头钎焊裂纹尖端两侧临近界面处应力高度集中,是导致其断裂失效的主要原因。基于ANSYS对PDC钻头钎焊裂纹进行数值模拟,针对焊缝裂纹形状、厚度、位置的不同,能对裂纹尖端应力场等值线图及应力强度因子进行数值计算。借助这一计算PDC焊缝裂纹应力强度因子的新方法,阐述了PDC断裂失效机理,用以指导钻头焊接工艺,稳定和提高PDC钻头焊接质量。

Highly concentrated stress near the interface on both sides of brazing seam tip is the main reason forfracture failure of polycrystalline diamond compact （PDC） bits. On the basis of ANSYS, numeric simulation wasconducted for brazing crack of PDC bit. Aiming at different shape, thickness and position of brazing seam, stressfield contours and stress intensity factors were calculated at the tip of cracks. With aide of this new method forcalculation of stress intensity factor, the paper described the mechanism of PDC fracture failure to guide the weldingprocess, stabilize and improve the quality of welding PDC bits.