Asphalt shingle hail resistance performance evaluation using numerical simulation methods

Hails impact on asphalt shingles causes huge economic losses every year. Numerical simulation of the hail impact process is essential for mitigation strategy development. In this dissertation, the objective is to develop a high-fidelity simulation model for the hail impacts on asphalt shingle. To properly model the hail during an intermediate-velocity impact process, the effectiveness of three simulation methods (Lagrangian method, Arbitrary Lagrangian-Eulerian method (ALE), and Smooth Particle Hydrodynamics method (SPH)) and three built-in material models from LS-DYNA® (MAT10, MAT13, and MAT155) were investigated. The performance of each combination of the simulation method and material model was evaluated by comparing the contact force results with the experimental results in the literature. The ALE method combined with MAT155 was shown to have the best performance on contact force profile prediction. The findings were further validated by a case study. Outcomes from this comparison provide insights into the selection of simulation method and material model for hail modeling in an intermediate-velocity impact scenario. The 3-tab fiberglass asphalt shingle was selected as the impact target among the other types of shingle due to its representativeness. Tensile tests were conducted on the in-plane samples of asphalt shingles and the fiberglass base mat (one of asphalt shingle’s important components). The elastic moduli of asphalt shingle and fiberglass mat were found to vary with the sample orientation angles. To better understand the mechanical behavior of asphalt shingles and to identify material properties that are difficult to obtain from experiments, the simplified representative volume element (RVE) model of asphalt shingles was developed, and the constituent material properties were estimated through optimization technique to correlate the simulation results with the experimental results. With the asphalt shingle RVE model, the effective orthotropic material model properties of the asphalt shingle were obtained, and the in-plane tensile test simulation results could reasonably match the experimental results. The effect of fiber volume ratio and constituent material properties on the asphalt shingle moduli were further investigated based on the asphalt shingle RVE model. The validated hail model and the shingle model were then applied to simulate the hail-asphalt impact scenario. With the currently available experimental data and literature, the failure and damage criteria of asphalt shingles remain unknown. The model was only applied to simulate the scenarios identified from experiments in which the shingle failure will not occur. It was found that both the impact location and the support condition will influence the hail resistance behavior of the asphalt shingle.

Embargo status: Restricted until 09/2023. To request the author grant access, click on the PDF link to the left.