错齿BTA钻头刀体扭转强度模拟分析与实验研究

Simulation and Experimental Study on Torsion Strength of Staggered BTA Drill Body

错齿BTA钻头刀体结构复杂,在钻削过程中既要承受较大的钻削力,又要具有足够大的排屑空间,解决刀体强度与排屑能力之间的矛盾是实现错齿BTA钻头优化设计的关键。采用有限元模拟分析与实验相结合的方法,对核电管板加工用错齿BTA钻头在扭转载荷作用下刀体强度及其应力应变分布特征进行了研究。结果表明:现有的错齿BTA钻头刀体在外齿根部与刀体中心两个排屑通道之间的横筋处为薄弱环节,存在较为严重的应力集中现象,扭矩实验中裂纹的产生部位与有限元模拟分析结果一致。通过采用形状优化及拓扑结构优化的方法对刀体薄弱环节进行优化改进,实现了刀体强度与排屑能力的综合优化,提高了错齿BTA钻头管板深孔加工效率。

In the light of complexity of BTA drill cutter body structure,processing of drilling not only need to be subjected to massive cutting load,it also demands sufficiently large space for chip removal,so the key to resolve the conflicts between strength and chip removal capacity is to achieve optimization design of BTA drill. Finite element analysis and experiments are applied to study the cutter body strength and stress-strain distribution of the BTA drill,which is for the tube sheets of nuclear power plants under torsion load. And the results show that the root of external insert and transverse reinforcement between the two chip of center cutter body and removal channels,which have a severe stress concentration issue,are its weakness to the existing BTA drill,and torque generated in the experiment parts and simulation results are consistent with each other. So the present results provide the basis for improving design for BTA drill. By optimizing the weak links of the cutter body with shape optimization and topology optimization,cutter body strength and chip removal capacity are optimized,processing efficiency of BTA drill on tube sheets of nuclear power plants are enhanced.