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纤维金属层板作为一种新型复合材料,已开始应用于航空航天领域。本文脱离传统应变测量方法,应用一种新测量方法-数字化光学应变法,实现了层板中金属层应变的测量;同时以子层刚度理论获得层板的等效刚度矩阵,修正经典层板理论中整体刚度矩阵的求解方法,实现了金属层应力更准确预测。以纤维增强铝锂合金2/1及3/2层板为例,使用光学应变法测量其金属层应变进而计算金属层应力,利用有限元仿真分析、经典层板理论及修正方法分别对其进行金属层应力预测。通过对比光学应变测量结果和有限元仿真结果,2/1及3/2层板光学应变测量结果与仿真结果最大误差分别为2.12%和3.68%,验证了新测量方法的准确性及实用性;通过对比光学应变测量结果和层板理论预测结果,2/1及3/2层板模型修正后结果比修正前准确率分别提升了2.91%和5.83%,验证了修正模型的有效性及先进性。
As a new type of composite material, fiber metal laminates have been used in aerospace field. In this paper, we deviate from the traditional strain measurement method, using a new measurement method - the digital optical strain method, to measure the strain of the metal layer in the laminates; at the same time, obtain the equivalent stiffness matrix of the laminates based on the sub-layer stiffness theory, In the global stiffness matrix solution method to achieve a more accurate prediction of metal layer stress. Taking the fiber reinforced Al-Li alloy 2/1 and 3/2 laminates as an example, the optical strain method is used to measure the strain of the metal layer to calculate the stress of the metal layer. By using the finite element simulation analysis, the classical laminar theory and the correction method, respectively, Metal layer stress prediction. By comparing the optical strain measurement results with the finite element simulation results, the maximum errors between the optical strain measurements and the simulation results of 2/1 and 3/2 laminates are 2.12% and 3.68%, respectively, which verifies the accuracy and practicability of the new measurement method. By comparing the results of optical strain measurement and the theoretical prediction of laminates, the corrected results of 2/1 and 3/2 laminates improved by 2.91% and 5.83% respectively compared with that before correction, which verified the validity and advancement of the modified model .