Accelerated Simulations of Realistic Granular Soils Using PhysX Engine

点击翻译按钮获取中文摘要

Granular materials are ubiquitous in nature and in industrial applications; they include sands/gravels, ores, powders, chemicals, pharmaceuticals, and food products. In geotechnical engineering, sands and gravels are critical construction materials and their behavior is strongly related to geohazards, such as landslides and erosion. While numerical modeling of discrete particles is an emerging tool for the study of mechanical behavior of granular materials, rapidly generating and simulating a large number of realistic soil particles to model significant problems is still difficult. This research aims to overcome this limitation by investigating the accuracy and efficiency of a video gaming platform, which features high computational efficiency, in simulation of granular materials. The expected outcome of this research will be a new geo-simulator, which will improve the simulation accuracy, increase the number of realistic particles in simulations, and reduce simulation time. The new geo-simulator can be used in many disciplines and industries that deal with granular materials. For example, it could be used in construction, mining, and agricultural industries to optimize earthmoving machinery such as dump trucks, excavator buckets and harvesters to increase productivity and efficiency. The geo-simulator may also be used in the pharmaceutical, chemical, and food industries to optimize mixing, tablet coating, and separating processes to improve product quality and operational efficiency. With the scale at which granular material is processed in the US and in the world, large cost savings are likely to result. This geo-simulator will be integrated as a medium to reach out to middle-high school students, and the public to increase their interest in geotechnical engineering and STEM fields. This interdisciplinary research project aims to investigate the accuracy and efficiency of a PhysX gaming engine for accelerating simulations of realistic granular soils. The scope of this research relates to five important issues. First, triangular face tessellations will be used in PhysX to precisely preserve sharp corners of realistic particles. Second, the effectiveness of the simplified contacting model in PhysX will be validated by a miniature direct shear test that can be scanned by X-ray Computed Tomography. Third, an image-based shape sculpture technique will be integrated into PhysX that can generate realistic particles based on distributions of particle sizes and shapes. Fourth, PhysX will be extended and customized to include servo-control and post-processing functions to develop a new discrete element simulator GeoPhysX for geotechnical simulations (i.e., laboratory test and landslide simulations). Fifth, systematic parametric studies will be performed using validated GeoPhysX to analyze effects of particle shape and gradation on macro, local, and micro mechanical behavior of granular soils. This project will help to fill the knowledge gap that links micro particle properties and the macro mechanical behavior of granular soils, with the potential to enhance our current understanding of granular soils as construction and load-bearing materials, the porous matrix for flows and storage, and vulnerable components during failures and hazards.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.