金刚石框架锯锯切研究(Ⅸ)-锯条张紧变形和应力的有限元分析

Deflection and Distortion of Diamond Blade during Marble Frame Sawing

本文对国内外锯切张紧力的理论和测量研究结果、锯条的失稳倾斜进行了全面的综述,然后根据锯切力研究的数据,采用有限元法对不同加工条件下锯条锯齿焊接根部受力和锯条的变形等问题进行了研究。结果表明,在锯切过程中锯条与结块焊接边缘两侧出现应力最大值,因此较易产生疲劳裂纹;锯条的挠度随偏心力的增大而增大;不同结块位置上的锯条受到的力和变形是不同的;在通常的切削过程中,张紧力的存在可以保证锯条的刚性,但不可能因为锯条张紧力和切削力的抵消作用,使得锯条呈现直线状并切削。仅仅在合适的加工条件下,锯条在切削段的局部区域可能表现为相对较为平直和良好的切削接触状态。

Based on the previous studies of frame sawing process of marble by diamond blade, the pretension and the distortion were analyzed by non - linear finite element method. The deflection of blade, the strain and the stress of the blade especially on the welded point of segment on blade were calculated under different sawing condiyions, including sawing force per segment, segment spaces and the excentric distance of tension loading etc. . In general excentric loading on blade was considered to make the blade contact the stone in straight line during cutting process, this opinion was not supported by the results in this report, the blade was concavity notwithstanding with local flatten bottom in some cutting conditions. The deflection of blade were decided not only by excentric distance and pretension loading, but also by the cutting conditions such as the contact length between segments and stone, the sawing forces acted on different segments etc. The pretension will help avoiding the failure of blade caused by distortion. The stress on the welded point of segment was in the range of permission, but the fatigue caused by sawing forces must be considered further.