We study the implicit time discretization of Timoshenko prestressed beams. This model features two types of waves: flexural and shear waves, that propagate with very different velocities. We present a novel implicit time discretization adapted to the physical phenomena occuring at the continuous level. After analyzing the continuous system and the two branches of eigenfrequencies associated wit...

Prestressed Concrete Cylinder Pipe (PCCP) is a widely used water pipe all over the world. A major cause of PCCP failure is the internal wire break, which will emit acoustic signal. In this paper, a hydrophone-based PCCP real-time monitoring and failure-prediction system was proposed. By applying wavelet energy normalization analysis to signal feature extraction and Support Vector Machine (SVM) ...

Abstract In this publication, cold gas spraying (CGS) is investigated as an enabler for aluminum-steel joints. Using a powder-based coating process to adhere steel layer aluminum substrate allows component be welded the deposited by resistance spot welding. This method permits metallurgical connection between similar materials separated, while mechanical bonding ensures at dissimilar aluminum-t...

There are more than 130,000 prestressed concrete bridges in the United States with about 37,000 bridges being more than 30 years old. Prestressing steel strands are an important construction element used in these bridges and are critical to their performance. Presently there is no effective Nondestructive Evaluation (NDE) technology for condition assessment of these prestressing strands once th...

The problem of determining the effective incremental response of nonlinearly elastic composite materials given some initial prestress is of interest in numerous application areas. In particular, the case when small-amplitude elastic waves pass through a prestressed inhomogeneous structure is of great importance. Of specific interest is how the initial finite deformation affects the microstructu...

This paper deals with the economic optimization of reinforced concrete road vaults and with the optimization of rectangular hollow section bridge piers typically used in road construction. It shows the efficiency of a heuristic optimization by the threshold accepting algorithm. The evaluation of solutions follows the Spanish Code for structural concrete. Design loads are in accordance to the na...

The mechanical behavior of freestanding gold membranes 0.5 micron thick with and without passivation layers was studied with a membrane deflection experiment. Membrane width was varied from 2.5 to 20 microns to investigate size effects. The presence of the passivation layer had the effect of reducing the membrane strength. Yield stress, as well as fracture strain and stress, were all found to b...