The current study assesses the residual stresses and remnant damage caused by a spherical projectile impacting upon a flat surface. The immediate application of this information is to the problem of foreign object damage (FOD) associated with the ingestion of debris into an aircraft turbine engine and the subsequent reduction in component lifetime. The work is focused on two primary features: (...

Abstract—In this study, a general approach to the reliability based limit analysis of laterally loaded piles is presented. In engineering practice the uncertainties play a very important role. The aim of this study is to evaluate the lateral load capacity of free-head and fixed-head long pile when plastic limit analysis is considered. In addition to the plastic limit analysis to control the pla...

A passive micro strain gauge with a mechanical amplifier has been designed, analyzed, and tested. The mechanical amplifier provides a high gain such that residual strain in thin films can be directly measured under an optical microscope. This strain gauge can be in situ fabricated with active micro sensors or actuators for monitoring residual strain effects, and both tensile and compressive res...

Desorption of thiolate self-assembled monolayers (SAMs) seriously limits the fabrication of thiol-based devices. Here we demonstrate that nanoporous Au produced by dealloying Au-Ag alloys exhibits high electrochemical stability against thiolate desorption. Nanoporous Au has many defective sites, lattice strain and residual Ag on the ligament surface. First-principles calculations indicate that ...

We present a theoretical study of shaft-loaded blister test for the determination of the adhesion strength of thin polymer films and coatings to rigid substrates. The relationships among strain energy release rate, load, deflection and residual stress are fully investigated. A series of numerical results of finite element analysis allow us to verify the theory quantitatively and thus estimate t...

Laser materials processing normally induces a certain residual stress distribution in the target material. Distributions favoring microcrack propagation lead to reduced fatigue life of the material. This paper investigates the feasibility of altering the stress field by using underwater shock waves in the micron scale. Shock pressure was computed and the stress analysis was conducted, in which ...

in this work, dynamic mechanical properties of three high-manganese steels with trip/twip or fully twip characteristics are studied. high strain rate experiments in the range of true strain rates between ~500 and 1800 /s are conducted using a dynamic torsional testing setup. all the three steels show a positive strain rate sensitivity in the intermediate range of strain rates (up to 500 /s). bu...

Plastic deformation causes very small changes in the thermoelastic response of metallic materials; this variation of the thermoelastic constant has the potential to form the basis of a new non-destructive, non-contact, full-field technique for residual stress assessment that is quicker and cheaper than existing methods. The effect of plastic strain on the thermoelastic constant is presented as ...