the effects of isothermal aging at temperatures between 550-850 ?c for durations of 1-100 h on microstructure, tensile properties, and impact fracture behavior of 316l austenitic stainless steel weld metal have been investigated. for this purpose, various techniques including metallographic observations, measurement of ferrite content using ferritscope, and fractographic investigations have bee...

A plasticity-fracture constitutive model is presented for prediction of the behavior of confined plain concrete. A three-parameter yield surface is used to define the elastic limit. Volumetric plastic strain is defined as hardening parameter, which together with a nonlinear plastic potential forms a non-associated flow rule. The use of non-associated flow rule improves the prediction of the dil...

a new model is proposed for two-dimensional simulation of the concrete fracture in compression. the model generated by using the voronoi diagram method and with considering random shape and distribution of full graded aggregates at the mesoscopic level. the aggregates modeled by combining irregular polygons, which then is placed into the concrete with no intersection between them. by this new m...

In concrete pavements, a single concrete mixture design is selected to resist mechanical loading without attempting to adversely affect the concrete pavement shrinkage, ride quality, or noise attenuation. An alternative approach is to design distinct layers within the concrete pavement surface which have specific functions thus achieving higher performance at a lower cost. The objective of this...

Rapid advances are taking place to develop hydrogels of high stretchability and toughness, but fatigue fracture has not been studied for any hydrogels. This negligence hinders the development of hydrogels and their applications. Herewe initiate a study of fatigue fracture of hydrogels.We choose polyacrylamide hydrogel as a model material. To place fatigue fracture in context, we apply monotonic...

This paper analyses the fracture behavior of the brazed BCBN grain by comparison with brazed PCBN grain through grinding test of Nickel-based superalloy. The self-sharpening effect is created by timing micro-fracture behavior for BCBN abrasive grains, but by macro-fracture behavior for PCBN abrasive grains. During grinding with brazed BCBN abrasive grains, the material is removed together with ...

Concrete fracture behavior is predicted by one of multi-scaling methods, called the virtual internal bond (VIB) model. The VIB model describes the microscopic interactions between the cement pastes and aggregates using the concept of homogenization. The microscopic behavior is connected to macroscopic behavior by the Cauchy-Born rule, which results in the strain energy function. From the macros...

Microstructural, mechanical, and thermal-shock behavior of hot-gas candle fiters obtained from different manufacturers have been evaluated. These filters include both monolithic ceramic and composite materials. Based on the results obtained so far, composite filters perform better than monolithic ceramic filters in a thermal-shock environment. During thermal-shock testing, the monolithic cerami...