HEMTT Dynamic Sensitivity to Small Obstacles at Low Velocities. Volume 1, Field Tests.

摘要

U.S. Army Waterways Experiment Station conducted dynamic tests using the M977 Heavy Expanded Mobility Tactical Truck (HEMTT) in both the empty and loaded configuration crossing low profile linear obstacles in both vehicle tracks. The obstacle heights were: 0.25, 0.50, 0.75, 1.00, 1,50, 2.00, 2.50 and 3.00 inches. The tests were designed to simulate the process of weigh-in-motion (WIM). The data collected were also used in a separate study which validated a 2-dimensional dynamics model created, using the VEHDYN 3.0 code. The instrumentation consisted of: vertical accelerometers; rate transducers; and string potentiometers. The testing was conducted at two low velocities: 1.8 mph and 4.5 mph. Each test was repeated three times to achieve a data base on the range of vehicle responses to similar tests. The data were reduced in the form of: time histories, frequency analysis using an FFT, peak dynamic values versus obstacle height, maximum frequency amplitude versus obstacle height. Low velocity, Validation, HEMTT, Vehicle dynamics, VEHDYN 3.0, Pitch rate, Weighing-in-motion, Computer simulation, Accelerometers.