The Feasibility of Estimating Elastic-Plastic Strain in Powder Structural Steel with Different Residual Porosity by Magnetic Methods
The world’s output of products made of sintered powders is constantly growing due to high productivity and efficiency of powder metallurgy processe s. Safe operation of machine parts and structural components made of sintered powder ma t ials calls for reliable methods of nondestructive testing. The paper presents a procedure of t wo-parameter testing of product structure and porosity, as well as results of investigatio ns into the effect of tensile stresses on the magnetic characteristics of powder structural stee with different residual porosity; it also discusses the applicability of the results for estimat ing elastic-plastic strains.
Correlation between the stress-strain state parameters and magnetic characteristics of carbon steels
A method for reconstruction of the stress-strain diagrams of steel objects from their magnetic characteristics determined directly during tension has been suggested. The coercive force, residual induction in the major hysteresis loops, and the maximum magnetic permeability are recommended as parameters for nondestructive testing of stresses and strains.
A model for predicting heat transfer through gypsum‐board/wood‐stud walls exposed to fire
To facilitate the development of cost-effective and flexible design options there is a need to develop models to predict the fire resistance of wood-frame building assemblies. Such assemblies often derive much of their fire resistance from a protective membrane composed of gypsum board. A simple two-dimensional computer model is presented to predict heat transfer through gypsum-board/wood-stud walls exposed to fire. Input data for the thermophysical properties of gypsum board were measured exploying standard bench-scale tests. Input data for wood were selected from the literature. Small-and full-scale fire resistance tests were conducted on gypsum-board/wood-stud wall assemblies to provide data for the validation of the model. The model is shown to predict heat transfer through these walls rather well.