Dynamic Response, Residual Strength, and High Strain-Rate Failure Modes of Rock and Concrete
Abstract
At UCSD, we have initiated a fundamental research program in order to understand and quantify the dynamic response and failure modes of rocks and concrete, using a coordinated effort which involves material characterization, high-strain-rate experiments, and physically-based analytical-computational modeling. The work includes the following major tasks: I. Microstructural Characterization (1.1: Ultrasonic Measurements; 1.2: Microscopy; 1.3: Image Processing; 1.4: Statistical Measures), II. Mechanical Tests (11.1: Quasi-static Experiments; 11.2: Hopkinson Bar Experiments; 11.3: Gas Gun Experiments), 111. Model Experiments, IV. Physically-based Modeling, and V. Verification of Model Predictions. The research includes a set of carefully designed recovery experiments using UCSD's 2.5- and 6-inch gas guns and the 1.5-and 3-inch Hopkinson bars; the mechanisms and nature of shock-induced damage in the material are being studied. The strain rate, stress amplitude, and the total input energy are controlled in these tests. Both jacketed and unjacketed samples are used. Through the use of ultrasonic measurements, the degradation in the sample stiffness will be measured nondestructively. These measurements will then be correlated with microscopic observations of the specimens, using optical microscopy and SEM. Based on the knowledge gained through the above experimental observations, a set of new experiments is planned to study the residual strength and dynamic response of shocked materials. Once the dominant microstructural features are identified, model experiments will be designed to directly examine the damage evolution process.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 15, 2000
- Accession Number
- ADA377673
Entities
People
- Sia Nemat-nasser
Organizations
- University of California, San Diego