New Results of the Heat-Treated CuZn39Pb3 Brass Behavior and Resistance to Cavitation Erosion

The paper presents the results of the behavior and resistance to the erosion by vibrating cavitation of the CuZn39Pb3 brass, obtained by quenching the volume heat treatment from 800°C with water cooling, followed by the stress-relief to 250°C, with air cooling. Comparison with both the delivery status and the naval brass (used for ship propellers), based on the characteristic parameters values, recommended by the ASTM G32 standards and used in the Cavitation Laboratory of the Polytechnic University of Timisoara, shows that the hardness increase resulted from the heat treatment led to a significant increase of resistance to vibrating cavitation.

Thermal Stress Analysis of 3D Anisotropic Materials Involving Domain Heat Source by the Boundary Element Method

ABSTRACTIn engineering applications, it is pretty often to have domain heat source involved inside. This article proposes an approach using the boundary element method to study thermal stresses in 3D anisotropic solids when internal domain heat source is involved. As has been well noticed, thermal effect will give rise to a volume integral, where its direct evaluation will need domain discretization. This shall definitely destroy the most distinctive notion of the boundary element method that only boundary discretization is required. The present work presents an analytical transformation of the volume integral in the boundary integral equation due to the presence of internal volume heat source. For simplicity, distribution of the heat source is modeled by a quadratic function. When needed, the formulations can be further extended to treat higher-ordered volume heat sources. Indeed, the present work has completely restored the boundary discretization feature of the boundary element method for treating 3D anisotropic thermoelasticity involving volume heat source.

Bem Study of 3D Heat Conduction in Multiply Adjoined Anisotropic Media with Quadratic Domain Heat Generation

ABSTRACTIn engineering, it is quite often to have applications of the heat transfer of conduction having domain heat generation present inside. The paper aims to present boundary element formulations for analyzing the three-dimensional heat-conduction in dissimilarly bonded anisotropic media involving quadratic volume heat sources. In this paper, the additional volume integral present in the boundary integral equation is analytically transformed to the boundary surface for the volume heat sources modeled by quadratic functions. The technique of domain-mapping is employed to treat the three-dimensional anisotropic heat conduction in multiply adjoined media with proper interfacial conditions provided. For showing our successful implementation, a few example cases are analyzed with verification of independent analyses by the finite element method.