introduction: this study investigated the fatigue and fracture modes of race and protaper rotary instruments. materials & methods: fatigue resistance was evaluated by rotating the files 30 ° or 60 ° and with 2 or 5mm radius of curvature. race taper 06 size 25 and protaper f1 files (n=40) were used. the number of rotations to failure was analyzed by two-way anova and independent sample     t-tes...

In buildings with triangular plan, the center of mass and rigidity cannot geometrically match all possible directions of the earthquake. This will result in torsional moments in the stories causing the building to rotate around the center of rigidity. In this paper, via response spectrum analysis (RSA) and nonlinear static analysis, the seismic behavior of 5-, 10- and 15-story steel structures ...

in this research formability behavior and texture of st14 low carbon steels produced by foolad mobarakeh plant for deep drawing application had been studied. plate textures were characterized by x-ray diffraction technique. to evaluate formability behavior one dimensional tensile test was carried out and related parameters were recognized. moreover eriksson experiment and spherical pattern prin...

The influence of laser processing parameters on mechanical properties and microstructure of pure titanium models made by selective laser melting is investigated. The density of the models can reach higher than 95% under proper conditions. Although the tensile strength test shows results comparable to the wrought material, the impact and torsional fatigue strengths are low because of porosity an...

This article demonstrates a new approach for nonlinear finite element analysis. The methodology is very suitable and gives very accurate results in linear as well as in nonlinear range of the material behavior. Proposed methodology can be regarded as stress based finite element analysis as it is required to define the stress distribution within the structural body with structural idealization a...

Lightweight artificial muscle fibers that can match the large tensile stroke of natural muscles have been elusive. In particular, low stroke, limited cycle life, and inefficient energy conversion have combined with high cost and hysteretic performance to restrict practical use. In recent years, a new class of artificial muscles, based on highly twisted fibers, has emerged that can deliver more ...