ABSTRACT

Composite structures have been increasingly used in marine industries because of their high performance. During their service time, they may be exposed to extreme loading conditions such as underwater explosions. Both thermal loading effects on deformation and deformation effects on temperature need to be taken into consideration in the numerical simulations. Therefore, a thermomechanical analysis is conducted in a fully coupled manner, in order to investigate the thermal and mechanical responses of composite materials under explosion loads. In this study, the peridynamics theory is used for failure analyses of composite structures

INTRODUCTION

In recent years, composites have been employed in a variety of applications in marine structures. Their high performances such as high strength-to-weight ratios and reduced maintenance requirements give them a bright future in marine industries. In addition, these characteristics have garnered them recent attention as effective materials in military applications (LiVolsi, 2014). Military structures are frequently exposed to extreme loads in the field or at sea, thus the extreme loading conditions need to be considered in their design state without any compromises from their weights (Diyaroglu, 2016). In the realm of varies types of extreme loadings, the explosive loading or blast loading is a typical and critical one, which draws a lot of attentions in marine composites research. However, different types of material, i.e. fibre and matrix, are involved in the construction process of composites, making the properties of composites materials being rather complex. What's more, the highly nonlinear response of composites under explosion loads makes the analysis being more challenging. Therefore, various studies concentrate on this issue with the increasing abilities of modern computers.

In the safety analysis of composite marine structures, the failure mechanism study, or more specifically speaking, the crack propagation prediction is a critical factor. The investigation of this type of problem generally falls into three categories: analytical method, experimental study, and numerical simulation. Analytical method could provide relatively faster solutions compared to the other two methodologies. Hence, it is generally utilized in the initial design state of the composite marine structures without any computational cost. Librescu and Nosier (1990) developed a composite model which incorporated transverse shear deformation and transverse normal stress. Later on, Librescu et al. (2004) addressed the problem of the dynamic response of sandwich flat panels exposed to blast loadings analytically. Compared to the analytical method, the experimental studies may provide more information and give more intuitive senses. There are mainly two types of blast tests, i.e. in air and underwater. In comparison with the underwater tests on full-scale structures, laboratory tests have many advantages, for example, lower cost and easier implementation (Hall, 1989). In addition, scaling techniques are necessary to extend the damage parameters from the specimen level can be extended to the structural level (Rajendran, 2008; Rajendran et al., 2007). As to the third method, the numerical simulation method develops rapidly in recent years because of the increasing computer computing abilities. Dobyns (1981) conducted an analysis of simply-supported orthotropic plates subjected to static and dynamic loads. Batra and Hassan (2008) adopted the finite element method (FEM) to analyse the mechanical responses of several fibre-reinforced composite layers under explosion loading conditions. Leblanc and Shukla (2010) investigated the damage evolution and dynamic response of an E-Glass/Epoxy composite material with an underwater explosive loading condition. Numerical simulation was implemented by utilizing the commercially available LS-DYNA finite element code. And the simulation results were compared with the ones obtained from the experiments. Kazanci (2016) conducted a review on the response of blast loaded laminated composite plates.

This content is only available via PDF.
You can access this article if you purchase or spend a download.