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Haozhong Gu

Publications and source records attributed to Haozhong Gu.

A Benchmark Example for Delamination Propagation Predictions Based on the Single Leg Bending Specimen under Quasi-static and Fatigue Loading

Benchmark examples based on Single Leg Bending (SLB) specimens with equal and unequal bending arm thicknesses were used to assess the performance of delamination prediction capabilities in finite element codes. First, the development of the quasi-static benchmark cases using the Virtual Crack Closure Technique (VCCT) is discussed in detail. Second, based on the quasi-static benchmark results, additional benchmark cases to assess delamination propagation under fatigue loading are created. Third, the application is demonstrated for the commercial finite element code Abaqus Standard 2018. The benchmark cases are compared to results obtained from VCCT-based, automated quasi-static propagation analysis. A comparison with results from automated fatigue propagation analysis was not performed at this point since the current version of Abaqus does not include this capability under variable mixed-mode conditions. In general, good agreement between the results obtained from the quasi-static propagation analysis and the benchmark results were achieved. Overall, the benchmarking procedure proved valuable for analysis verification.

Ronald Krueger↗

Composite Progressive Delamination Analysis of Thin Ply Buckling

The NASA Advanced Composites Project is a multi-year consortium of government, industry and academia to develop and validate technology that will reduce development and certification of advanced composite materials for aircraft structures. One of its tasks is to simulate and predict composite damage progression accurately through high fidelity finite element models. It included a subtask to verify an approach based on the Virtual Crack Closure Technology (VCCT) as well as Floating Node Method (FNM). This paper discusses predicted damage onset and growth in a thin-ply buckling problem. Sensitivity of the simulations to various initial crack length is studied. The compressive load-displacement curves are plotted and the crack growth critical load is predicted. Overall, the crack progression follows simulation benchmarks well. However, the critical-load overshoot phenomenon is observed in both VCCT and FNM, suggesting further investigation may be worth pursuing.

damage progression↗