Ammar Mohamed M A, Shirinzadeh Bijan, Lai Kai Zhong, Wei Weichen
Robotics and Mechatronics Research Laboratory, Department of Mechanical and Aerospace Engineering, Monash University, Clayton 3800, Australia.
Department of Mechanical Engineering, Faculty of Engineering, Alexandria University, Alexandria 11432, Egypt.
Sensors (Basel). 2021 Nov 9;21(22):7447. doi: 10.3390/s21227447.
The current study presents three calibration approaches for the hole-drilling method (HDM). A total of 72 finite element models and 144 simulations were established to calibrate the measurements of the strain sensors. The first approach assumed the stresses acted on the boundaries of the drilled hole and thus analyzed the surrounding displacements field. The second analysis considered the loads on the outer surfaces of the specimen while measuring the strains' differences between the model with and without the drilled hole. The third approach was more comprehensive as it considered the mechanical and thermal effects of the drilling operations. The proposed approaches were applied to two different materials (AISI 1045 and CFRP). The steel specimens were machined using a CNC lathe while the composite laminates were manufactured using the robotic fiber placement (RFP) process. Subsequently, the residual stresses (RSs) were measured using the HDM. The obtained data were compared with X-ray diffraction measurements for validation. The results showed better estimation of the RSs when utilizing the third approach and clear underestimation of the stresses using the second approach. A divergence in RSs values between the three approaches was also detected when measuring the stresses in the internal layers of the composite laminates.
本研究提出了钻孔法（HDM）的三种校准方法。总共建立了72个有限元模型和144次模拟，以校准应变传感器的测量结果。第一种方法假设应力作用在钻孔边界上，从而分析周围的位移场。第二种分析在测量有钻孔模型和无钻孔模型之间的应变差异时，考虑了试样外表面上的载荷。第三种方法更为全面，因为它考虑了钻孔操作的机械和热效应。所提出的方法应用于两种不同的材料（AISI 1045和CFRP）。钢试样使用数控车床加工，而复合层压板则采用机器人纤维铺放（RFP）工艺制造。随后，使用钻孔法测量残余应力（RSs）。将获得的数据与X射线衍射测量结果进行比较以进行验证。结果表明，使用第三种方法时对残余应力的估计更好，而使用第二种方法时对应力的明显低估。在测量复合层压板内层的应力时，还检测到三种方法之间残余应力值的差异。
