the present study utilizes an analytical method to formulate the three lowest modal frequencies of axially-loaded notched beam through both crack location and load level in a specific format that can be used in existing frequency-based crack-identification methods. the proposed formula provides a basis to shift into two states, one with axial loading and the other without any loading whatsoever...

The paper presents FE-results on the behaviour of concrete under plane strain conditions. The material was modelled using a simple isotropic damage continuum model. The model was enriched by non-local terms to avoid a pathological mesh-sensitivity and to obtain a well-posed rate boundary value problem. The constitutive model was used to simulate localization of deformation in 3 benchmark proble...

The testing of mode III and mixed mode failure is every so often encountered in the dedicated literature of mechanical characterization of brittle and quasi-brittle materials. In this work, the application of the mixed strain displacement ε − u finite element formulation to three examples involving skew notched beams is presented. The use of this FE technology is effective in problems involving...

i) Install the un-notched beam (see Fig. 1) in the four-point flexure loading fixture ii) Attach the load pan (Note: The combined pan/fixture mass is ~0.980 kg) iii) Apply two10-kg masses one at a time to the load pan. iv) With the polarizer and analyzer crossed (dark field), focus the camera, and record the image using the thermal printer v) Determine the maximum fringe orders at the top and b...

The present study utilizes an analytical method to formulate the three lowest modal frequencies of axially-loaded notched beam through both crack location and load level in a specific format that can be used in existing frequency-based crack-identification methods. The proposed formula provides a basis to shift into two states, one with axial loading and the other without any loading whatsoever...

A compact dual band-notched Ultra-Wideband antenna with sharp band-notched characteristics and controllable notched bandwidths is presented. The antenna consists of a spade-shaped microstrip-fed Ultra-Wideband planar monopole antenna and two sets of band-notched structures. The band-notched structures are employed to generate the desired lower and upper rejection bands with good frequency selec...

Abstract The surface fracture toughness is an important mechanical parameter for studying the failure behavior of air plasma sprayed (APS) thermal barrier coatings (TBCs). As APS TBCs are typical multilayer porous ceramic materials, direct applications traditional single edge notched beam (SENB) method that ignores those structural characters may cause errors. To measure more accurately, effect...

Finite Fracture Mechanics and Cohesive Crack Model can effectively predict the strength of plain, cracked or notched structural components, overcoming classical drawbacks Linear Elastic Mechanics. Aim present work is to investigate size effects by expressing each model as a unified system two equations, describing stress requirement energy balance, respectively. Brittle crack onset in different...

An adaptive strategy for nonlinear finite-element analysis, based on the combination of error estimation and h-remeshing, is presented. Its two main ingredients are a residual-type error estimator and an unstructured quadrilateral mesh generator. The error estimator is based on simple local computations over the elements and the so-called patches. In contrast to other residual estimators, no fl...