Numerical Investigation of Delamination in Drilling of Carbon Fiber Reinforced Polymer Composites
- PDF / 4,737,207 Bytes
- 21 Pages / 439.37 x 666.142 pts Page_size
- 121 Downloads / 214 Views
Numerical Investigation of Delamination in Drilling of Carbon Fiber Reinforced Polymer Composites Wenliang Tang 1 & Yan Chen 1 & Haojun Yang 1 & Hua Wang 1 & Qiwei Yao 1
Received: 31 January 2018 / Accepted: 8 February 2018 # Springer Science+Business Media B.V., part of Springer Nature 2018
Abstract Drilling of carbon fiber reinforced polymer (CFRP) is a challenging task in modern manufacturing sector and machining induced delamination is one of the major problems affecting assembly precision. In this work, a new three-dimensional (3D) finite element model is developed to study the chip formation and entrance delamination in drilling of CFRP composites on the microscopic level. Fiber phase, matrix phase and equivalent homogeneous phase in the multi-phase model have different constitutive behaviors, respectively. A comparative drilling test, in which the cement carbide drill and unidirectional CFRP laminate are employed, is conducted to validate the proposedmodel in terms of the delamination and the similar changing trend is obtained. Microscopic mechanism of entrance delamination together with the chip formation process at four special fiber cutting angles (0°, 45°, 90° and 135°) is investigated. Moreover, the peeling force is also predicted. The results show that the delamination occurrence and the chip formation are both strongly dependent on the fiber cutting angle. The length of entrance delamination rises with increasing fiber cutting angles. Negligible delamination at 0° is attributed to the compression by the minor flank face. For 45° and 90°, the delamination resulted from the mode III fracture. At 135°, serious delamination which is driven by the mode I and III fractures is more inclined to occur and the peeling force reaches its maximum. Such numerical models can help understand the mechanism of hole entrance delamination further and provide guidance for the damage-free drilling of CFRP. Keywords CFRP . Hole entrance delamination . Failure mechanisms . Finite element analysis
* Yan Chen [email protected]
1
College of Mechanical and Electrical Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China
Appl Compos Mater
1 Introduction Carbon fiber reinforced polymer (CFRP), a kind of advanced composites, has been broadly used in various vital fields including aerospace, automobile and sports due to desirable mechanical properties such as high specific strength, high specific stiffness and corrosion resistance [1–3]. The increasing use of CFRP has placed higher demands on the machining operations. Unlike the conventional homogeneous metal materials, CFRP is a complex multiphase, anisotropic material, which complicates the nature of the material removal in machining process [4]. Since drilling is the most frequently employed machining operation to produce riveted and bolted joints, the poor quality of machined holes impairs the precision of composite components severely [5]. With regard to drilling quality of CFRP, some drawbacks including the hole exit delamination (pus
Data Loading...
