Evaluation of LS-DYNA MAT162 for Modeling Composite Fastener Joints for High Rates of Loading

In the present work, the behavior of composite-fastener joints in bearing failure at dynamic stroke rates of 500 in/s, 300 in/s and 100 in/s has been evaluated through progressive damage analysis (PDA) material model in LS-DYNA, namely MAT162. Two joint types: titanium pin and Hi-Lok fastener were analyzed to identify the differences between without and with preload conditions. A meso-level approach where each lamina was modeled separately was employed and a contact definition based on fracture toughness data was defined to represent composite delamination behavior. Test fixture had been modeled in a detailed manner to account for the dynamic effects and the simulation results were validated against experimental data. Preliminary test-analysis correlation indicated that MAT162 predicted results conservatively when compared to tests. Debris accumulation were observed to greatly affect the test results which were not considered in the current modelling strategies

Prediction of Low-Velocity Face-on Impact Response of Composite Laminates using High-Fidelity Finite Element Modeling Techniques

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140606/1/6.2016-2184.pd

Bending of composite cylindrical shells with circular cutouts: Experimental validation

An experimental study of unstiffened graphite-epoxy cylindrical shells with cutouts subjected to bending load is presented. Two cylinders were tested: a classical laminated cylinder with constant-stiffness and a fiber-steered cylinder with variable stiffness in circumferential direction. Both cylinders were tested until collapse in displacement control. Displacements and strains were measured by displacement sensors, strain gauges, and two digital image correlation systems. Analysis of the test data indicates that the highest stressed area was the edges of the cutouts where local displacements created large compression strains. The experimental data were compared with progressive damage analysis results obtained with a finite element analysis that included measured geometrical imperfections. The research contributes to the knowledge of variable-stiffness composite structures and their applications in aircraft fuselages

Face-on and edge-on impact response of composite laminates

This paper presents comprehensive experimental and numerical studies on the face-on and edge-on impact behavior of composite laminates. Experimental work is focused on finding the impact energy limits for barely visible impact damage (BVID) when a laminated composite plate is impacted either on its face or an edge. High-fidelity finite element analysis (FEA) model utilizing Enhanced Schapery theory (EST) combined with Discrete Cohesive Zone Model (DCZM) is developed to predict the response of the laminated composite plate subjected to face-on and edge-on impact loading. Predictions from the proposed high-fidelity FEA model are compared against experimental data and it is shown that the numerical results agree well with the test data. © 2015, American Institute of Aeronautics and Astronautics. All Rights Reserved