composites materials are widely used because of their high specific stiffness and strength. although the methods and techniques of designing these materials are well developed, however, the research on the behavior of these materials under impact and dynamic loadings are still under progress. in this article the crushing and energy absorption of composite tubes under axial dynamic loadings are ...

Lattice boom used on the crawler crane are welded by slender high strength steel tubes. Many studies show that actual bearing capacity of high-strength tubes is higher than stability calculated according to specification. To obtain and apply it engineering practice, a series axial loading tests carried out two kinds 20Mn2 S890 their damage load. By handling test data, coefficient fitting correc...

Increasing material’s strength is of particular importance. Improving material’s mechanical properties such as strength could reduce the size and weight of the structure. The size and weight of the structure are among the effective parameters in design. Since the past a variety of methods have been developed to increase the strength of metals that are capable of increasing metals’ strength to a...

severe plastic deformation (spd) methods were developed for producing of metals and alloys with ultrafine grained (ufg) microstructures having high strength. parallel tabular channel angular pressing (ptcap) as a noble severe plastic deformation (spd) method was used to produce ultrafine grained (ufg) and nanostructured cu-30%zn tubes. in this paper, the effect of ptcap process temperature on t...

Manufacturing and Testing techniques were investigated for the development of efficient joining of composite tubes. The stepped lap joining arrangements were studied. Finite element models were developed using ANSYS finite element code for predicting the stress distribution of the joint under the applied loads. Tubes made of graphite/epoxy were considered. The tubes were tested under both tensi...

We present three-dimensional numerical simulations of the dynamic evolution of uniformly buoyant, twisted horizontal magnetic flux tubes in a three-dimensional stratified convective velocity field. Our calculations are relevant to understanding how stratified convection in the deep solar convection zone may affect the rise and the structure of buoyant flux tubes that are responsible for the eme...

In recent years, high-strength steel has been used extensively for infrastructures because of its many advantages, such as ductility and strain-hardening properties, which are inferior to those ordinary structural steel, the small dimensions elements, lead greater freedom elegance in design, resulting lighter structures. practice, imperfections residual stresses due welding process pre-buckling...

BACKGROUND Molar bonding procedures need continuous improvement to be widely accepted clinically and eventually replace molar bands. MATERIAL AND METHODS The purpose of this study was to determine the effects of enamel micro-abrasion and silane coating of the base of molar tubes on shear and tensile bond strengths of orthodontic molar tubes. A total of 200 third molars were randomly allocated...