Experimental Mechanics

Abstract

Mechanical failure of machine parts, structures, and microelectronic components has a strong negative impact on the safety, security, and productivity of our people. Prevention of these failures is a principal focus of solid mechanics, which uses analysis, experiment, and computation to provide the understanding necessary for failure reduction through improved design, fabrication, and inspection. Experimental mechanics plays a critical role in this effort since it provides the data base for the calculations and the means for testing the validity of proposed theoretical models of failure. Current trends in experimental mechanics show increased use of optical methods for monitoring the displacements, velocities, and strains of surfaces. This trend has gained impetus from the attractiveness of noncontact methods for hostile environments and dynamically loaded bodies. Advances in laser technology have enhanced the instrumentation associated with these methods. Another trend is the investigation of material behavior under more complex loading conditions, made possible by the availability of servo-controlled testing machines with computer interfaces. Still another trend is the increased attention given to defects, such as inclusions, cracks, and holes, because of their importance in failure mechanisms. Opportunities for future contributions from experimental mechanics appear to be great and to occur across a broad range of technological problems. A central theme of future research appears to be increased emphasis on measurements at the micron and submicron scale in order to advance the understanding of material response and failure at the micromechanical level. Increased attention will also be given to internal measurements of defects, deformations and residual stresses because of their importance in developing a fundamental understanding of failure. Automated data reduction and control of experiments will greatly increase the information obtained from experiments and its usefulness for the development of mathematical models. Other important research directions include improved methods for measurements of in situ stresses in rocks, improved measurements of displacements and physiological parameters in biological systems, capability for long-term monitoring of the integrity of structures, and improved sensors for feedback control of mechanical systems.