Analysis of tensile damage characteristics of single filled bolt hole in laminate

• Published in: Polymer composites Vol. 44; no. 6; pp. 3153 - 3168
• Main Authors: Zhang, Fa, Zhang, Huanshi, Pan, Zhongxiang, Liu, Meina, Liu, Tierang, Wan, Yumin
• Format: Journal Article
• Language: English
• Published: Hoboken, USA John Wiley & Sons, Inc 01.06.2023; Blackwell Publishing Ltd
• Subjects: Bolted joints; Crack arrest; Crack initiation; Crack propagation; Damage; damage characteristics; Design engineering; Envelope curves; failure criterion; Failure modes; failure prediction; filled bolt hole; Laminates; Residual strength; Stiffness; tension
• ISSN: 0272-8397; 1548-0569
• DOI: 10.1002/pc.27308

The strength of filled bolt holes of composites is an important parameter in developing the bearing bypass envelope curves for bolted joint structures in engineering design. This paper presents the procedures of tensile failure strengths and damage for a laminate with a filled bolt hole. Tests of two different cases, open‐hole tension (OHT) and filled‐hole tension (FHT), were performed and repeated seven times, respectively. A new type of virtual testing based on the LaRC05 criteria coupling with XFEM crack technique was developed to predict and analyze the crack initiation and early propagation around the bolt hole in the laminates. Two analytical methods were also adopted to predict the residual strength for a laminate after drilling. The results show that the thinner sample would present a higher strength with the same material system. It is also shown that the virtual test can well capture the failure modes, revealing that the 0° fiber has a natural function of crack arrest, the 90° layers that are the fracture pioneers with matrix tensile failure trigger the fiber breakage of 0° layers, and the failure of 45° layers occurs at the last. Additionally, an interesting phenomenon is observed that the initial failure around the filled hole edge does not affect the structural stiffness. Finally, a good agreement is achieved among the experimental, analytical and numerical results. It suggests that the results could provide a valuable guidance for the design of multi‐bolted joint structure. This paper presents the procedures of tensile failure strengths and damage for laminate with a filled bolt hole. A new virtual testing for single filled bolt hole is developed based on the LaRC05 criteria coupling with extended finite element method (XFEM) crack technology. Additionally, three prediction models for the strength of the filled bolt hole plate are evaluated.