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为研究预压紧力对叠层结构制孔层间间隙的影响,本文首先采用板壳理论建立叠层结构制孔简化模型;进而运用有限元方法,分析了预压紧力对叠层结构制孔层间间隙的影响,并以单层板的受力响应模型进行结果比对以验证模型正确,进而分析了不同工艺条件下,叠层结构层间间隙的变化规律;最后通过叠层结构钻削试验验证了限元分析结果的正确性.研究结果表明,随着单向预压紧力的逐渐增大,叠层板会经历层间间隙逐渐减小到贴合的过程,其转折点对应着预压紧力的临界值.加工过程中欲达到良好的毛刺抑制效果,预压紧力需满足以下两个条件:Ⅰ)转折点对应的层间间隙D_B需小于未施加预压紧力情况下的层间毛刺高度;Ⅱ)其值需高于临界预压紧力F_B.此外,减小制孔轴向力或预压紧环直径可有效降低临界预压紧力及对应层间间隙;从提高预压紧力作用效果,减小层间间隙的角度考虑,叠层结构制孔时应将尺寸较厚、模量较高的板材置于叠层结构下层.
In order to study the influence of pre-compaction on the gap between layers, the paper first uses the shell theory to establish a simplified model of the hole structure of the laminated structure. Then the finite element method is used to analyze the effect of pre-compaction on the laminated structure The influence of the gap between the layers of the hole and the comparison of the results of the model with the stress response of the single-layer plate to verify the correctness of the model and then analyze the variation rules of the gap between the layers under different technological conditions. Finally, The test results verify the validity of the finite element analysis results.The results show that with the unidirectional preload increasing gradually, the laminate will experience a gradual decrease in the gap between the layers to the bonding process, the turning point corresponds to Pre-compaction critical value. To achieve a good glitch suppression during machining, the pre-compaction force must meet the following two conditions: Ⅰ) The inter-layer gap D_B corresponding to the inflection point should be smaller than that in the case of no pre-compaction Layer burr height; Ⅱ) its value should be higher than the critical pre-pressing force F_B. In addition, reducing the hole axial force or pre-stressing ring diameter can effectively reduce the critical pre-stress and the corresponding gap between the layers; Pre-crushing effect, reduce the interlayer Gap viewpoint, when the hole-size laminated structure thicker, higher modulus laminate sheet material disposed underlying structure.