Calculation Method Of Strength Research Articles

Comparative study of tensile tests based on Hopkinson bar for recycled aggregate concrete

To comparatively study the tensile properties and fracture patterns of recycled aggregate concrete with various replacement percentages (i.e. 0%, 25%, 50%, 75%, and 100%) of recycled coarse aggregate, the dynamic direct tensile tests, splitting tests, and spalling tests of recycled aggregate concrete in the strain-rate range of 100–102 s−1 were carried out using large diameter (75 mm) split Hopkinson tensile bar and pressure bar. Test results show that for recycled aggregate concrete, the quasi-static direct tensile strength is more marvelous than its quasi-static splitting strength. When recycled coarse aggregate replacement percentage is 0%–75%, the replacement percentage impact minimally on the quasi-static tensile strength of recycled aggregate concrete. In dynamic tensile tests, there exists apparent difference between the dynamic direct tensile strength and dynamic splitting. The dynamic tensile strength of recycled aggregate concrete increases with the increase of average strain-rate in all three kinds of tests. The average strain-rate affects the damage form of recycled aggregate concrete, which indicates that the recycled aggregate concrete has obvious rate sensitivity. There shows no obvious regularity between the dynamic tensile strength and the recycled coarse aggregate replacement percentage. And the indirect tensile strength calculation method used in this article offers the theoretical basis for the engineering application of recycled aggregate concrete.

Stress and Strength Analysis of Non-Right Angle H-section Beam

In this paper, according to the design requirements of a steel structural project, based on the principle of structural mechanics of thin-walled bar, the non-right angle H-section, which is subjected to bending moment and shear force, is taken as the object of study, the formulas of bending normal stress and shear stress are deduced. On this basis, the distribution of bending stress and shear stress and the location of dangerous stress are analyzed, the calculation method of section strength is discussed, and the FEA software ABAQUS is used to verify the above.

Совершенствование методики расчета на прочность фланцевых соединений

Совершенствование методики расчета на прочность фланцевых соединений

DEVELOPMENT OF NON-GLUED MASSIVE HOLZ SHEAR WALL AND PROPOSAL OF CALCULATION METHOD OF ALLOWABLE STRENGTH

DEVELOPMENT OF NON-GLUED MASSIVE HOLZ SHEAR WALL AND PROPOSAL OF CALCULATION METHOD OF ALLOWABLE STRENGTH

Experience in Applying the Technique of Improved Reservoir Calculation for the Modernization of DC Motors for Operation at Increased Frequency of Rotation

In this article, we consider DC direct-current motors used in special responsible electric drives, for example, autonomous small-size systems operating in short-time modes, namely, their modernization and the resulting problems in calculating the strength of the collector. The solution of these tasks is required in connection with the new operating conditions of the reservoir, since modernization is associated with increased power, including through increased rotational speed. The article presents the results of the development and application of the method of strength calculation of a reservoir, which specifies the values of stresses arising as a result of tightening the conditions of the collector and the electric motor as a whole. The characteristics of the real samples produced from the results of the studies are an indicator, first, the adequacy of the proposed calculation technique, and secondly, the applicability of this technique in industry.

Static calculations in the context of sewer pipe sliplining by polymer hose

The growing deterioration and unsatisfactory technical condition of the pipes of water supply and wastewater disposal networks in Russian cities and other inhabited localities, as well as limited (under the conditions of Russian housing and utilities sector reforming) funding of pipeline renovation and rehabilitation have considerably aggravated the problem of pipe reliability provision. These factors make pipe renovation and rehabilitation quite a topical issue. A very promising trend in the field of pipeline construction and renovation named “trenchless technologies” has been commonly used in the world in recent years. A wide choice of different construction materials used for pipe rehabilitation appeared in the market. Under the conditions of densely built-up urban areas, these methods are of great current interest for city utilities. Quite different pipe renovation methods are used currently but the most popular method comprises the application of a flexible polymeric hose that makes it possible to form a new composite pipe inside the old one. The wall thickness of such a hose is among the important factors that have an impact on the cost and efficiency of pipe renovation methods based on the application of flexible polymeric hoses. The hose wall thickness is determined on the basis of calculating the “soil - old pipe - hose” system in view of its static stability. The article describes the technology for the trenchless rehabilitation of water pipes and the strength calculation method for a “pipe - polymeric hose” double-layer structure.

Calculating the strength of water pipes for their rehabilitation with the application of polymer hoses

Such factors as: the growing deterioration and unsatisfactory technical condition of the pipes of water supply and wastewater disposal networks in Russian cities and other inhabited localities, as well as limited (under the conditions of Russian housing and utilities sector reforming) funding of pipeline renovation and rehabilitation have considerably aggravated the problem of pipe reliability provision. These factors make pipe renovation and rehabilitation quite a topical issue.A very promising trend in the field of pipeline construction and renovation named “trenchless technologies” has been commonly used in the world in recent years. As a result of this, a wide choice of different construction materials used for pipe rehabilitation appeared in the market. Under the conditions of densely built-up urban areas, these methods are of great current interest for city utilities. Quite different pipe renovation methods are used currently but the most popular method comprises the application of a flexible polymeric hose that makes it possible to form a new composite pipe inside the old one. The wall thickness of such a hose is among the important factors that have an impact on the cost and efficiency of pipe renovation methods based on the application of flexible polymeric hoses. The hose wall thickness is determined on the basis of calculating the “soil – old pipe – hose” system in view of its static stability. The article describes the technology for the trenchless rehabilitation of water pipes and the strength calculation method for a “pipe – polymeric hose” double-layer structure.

Calculation Method of shear strength of vertical stiffener connections to L-CFST columns

Based on the low cyclic loading test results of vertical stiffener connections between L-shaped columns composed of concrete-filled steel tubes and steel beams, a simplified trilinear model to pred...

A method for strength calculation of a shaft of wells' sinker

A method for strength calculation of a shaft of wells' sinker

The Influence of Loads Superposition, Deterioration Due to Cracks and Residual Stresses on the Strength of Tubular Junction

In the paper the interaction of several loads like pressure, axial force, bending moment and torsional moment are analyzed, taking into account the deterioration due to cracks and the influence of residual stresses. A nonlinear, power law, of structure material is considered. General relationships for total participation of specific energies introduced in the structure by the loads, as well as for the critical participation have been proposed. On these bases: - a new strength calculation methods was developed; � strength of tubular cracked structures and of cracked tubular junction subjected to combined loading and strength were analyzed. Relationships for critical state have been proposed, based on dimensionless variables. These theoretical results fit with experimental date reported in literature. On the other side stress concentration coefficients were defined. Our one experiments onto a model of a pipe with two opposite nozzles have been achieved. Near one of the nozzles is a crack on the run pipe. Trough the experiments the state of stress have been obtained near the tubular junction, near the tip of the crack and far from the stress concentration points. On this basis the stress concentration coefficients were calculated.

EVALUATIONS OF REMAINING STRENGTH ESTIMATION METHOD BY USING PLATE GIRDER MODELS WITH CORROSION UNDER SLEEPERS

In steel railway bridges with open deck system, the local buckling of compressive flanges under sleepers on plate girders caused by the local corrosion of flanges leads to the collapse of bridges. The local corrosion is thought to have a substantial impact on the ultimate strength of main girders. However, past research on ultimate strength contains few inquiries into the relationship between the local corrosion of compressive flanges and the ultimate strength of main girders, and a method of evaluating the relationship has not yet been established. In this study, parameter analyses that focus on plate girders with local corrosion under sleepers have been conducted by using full-scale plate girder models subjected to bending and local loads simultaneously. Then based on these analytical values and other existing experimental values, the study verified the applicability of the separate evaluation equations that we previously proposed for remaining load bearing capacity under bending and local loads respectively, as well as the remaining strength calculation method based on the strength interaction curve of plate girders subjected to bending and local loads simultaneously to clarify that ultimate strength can be evaluated with a high degree of accuracy.

Optimisation and assessment of theoretical impurity line power coefficients relevant to ITER and DEMO

Total radiated line power coefficients for ions of medium to heavy weight elements, called coefficients in the atomic data and analysis structure, have been improved by algorithmically optimising the selection of configuration sets that underpin the calculation to include the most important radiating transitions driven by both the ground and metastable configurations and to establish and limit the error of truncation. The optimised calculations typically differ from Pütterich by 20%–30% with truncation error . Further appraisal of error due to atomic level bundling, atomic structure and collision strength calculation methods has been carried out. It is shown that bundling to configurations is accurate to for all ions except those with closed-shell ground configurations which give errors up to a factor 2–3. For near neutral, closed-shell ions, plane-wave Born collision strength calculations, which omit spin-change, give substantial error in comparison with distorted-wave calculations of . For highly charged ions, spin-system breakdown reduces the error in the markedly, typically . The error introduced by the atomic structure codes used here, autostructure and the Cowan code, is probably limited to .

Reliability calculation method of longitudinal ultimate strength of ships under extreme sea conditions

Reliability calculation method of longitudinal ultimate strength of ships under extreme sea conditions

The research of bearing capacity of reinforced concrete beam with use combined experimental-computational method

The article shows results of behavior research of reinforced concrete beam exposed to fire using standard “time-temperature” curve. Practice of fire resistance estimating for reinforced concrete beams based on experimental and calculation method was developed and tested on the basis of the study results. Block diagram of temperature determining algorithm for nodal points of the cross-section by interpolation of temperature values in measurement points of the cross-section was showed. The fire test of reinforced concrete beams was carried out and a temperature distribution in cross-section of beams was defined based on it by application of interpolation techniques developed. The sequence of procedures of the strength calculation method based on temperature measuring in the inner layers of reinforced concrete beams was demonstrated. Fire resistance of the reinforced concrete beams under question was evaluated based on the interpretation of the data obtained during the fire tests and using the proposed method of strength calculating.

A semi-analytical analysis on beam-column ultimate strength with different initial deflections

Purpose A new beam-column ultimate strength calculation method has been developed and compared with nonlinear finite element analysis by ANSYS and ABAQUS. Design/methodology/approach A computer code ULTBEAM2 based on this method has been used for one and three span beam-columns with I-shaped cross-section under axial compression. Findings This paper studies the ultimate strength of beam-columns with various initial deflections of different shapes and magnitudes. Originality/value The comparison of ULTBEAM2 and finite element analysis shows good agreement for all cases with different initial deflections.

Применение метода конечных элементов при расчете трехслойных балок

authors of this article note that one of the widely used in practice methods of strength calculation of structures is the finite element method (FEM). FEM is a procedure of approximate solution of differential equations. It was originally designed for solving problems related to the calculation of strength of structures, that is, to calculate forces, stresses and strains in solids.

Dynamic strength measurement of aluminum under magnetically driven ramp wave pressure-shear loading

The strength of a material at high pressure is an important physical parameter in shock physics and material science. In this work, a magnetically applied pressure shear loading technique, combining magnetically driven longitudinal and shear waves, was developed to measure material strength in high pressure and high strain rate experiments. Using theoretical and numerical analysis, we obtained a relationship between the deviatoric stresses and the yield stress, and demonstrated the strength calculation method. Experiments were then conducted on pulsed power generator CQ-4, with a newly established quasi-static magnetic field generator to produce shear stresses, and transverse velocity measurement techniques to determine the results. The experiments measured the strength of polished and cold rolled aluminum at high pressure. The strength of polished aluminum agreed well with previous data measured using self-consistent methods under ramp wave loading. The strength of cold rolled aluminum was larger due to differences of initial plastic deformation. Meanwhile, the strength of both polished and cold rolled aluminum increased with pressure.

Direct measurement of material dynamic strength under high pressure using magnetically driven pressure-shear loading

Material strength measurement under high pressure is a long goal of impact dynamics. In this work, we report a new method for directly measuring material dynamic strength under high pressure, viz. magnetically driven pressure-shear loading technique. The relations of deviatonic stresses and yield stress under pressure-shear loading were analyzed, and simple functions of deviatonic stresses and yield stress were obtained under complex stress state. Using LS-DYNA code, evolutions of deviatonic stresses and Von-Mises stress in sample under ramp wave pressure-shear loading were simulated, and calculation method of material strength is given. Based on numerical simulations results, magnetically driven ramp wave pressure-shear experiments were conducted on pulsed power generator CQ-4, with established quasi-static magnetic field generator and transverse velocity measurement techniques, to explore dynamic strength of aluminum at high pressure. Reliable experimental results are obtained. The results show that, as a potential new technique, magnetically driven pressure-shear combination loading has great application prospect in material dynamic strength measurement under high pressure.

Nośność powierzchniowa przekładni zębatych o kołowo-łukowym zarysie zębów typu Nowikowa

Article presents the algorithm for obtaining maximum surface stresses for Novikov gears. Described surface strength calculation method is based on Hertz theory of two bodies being in point contact. What’s more the influence of gear position errors on maximum contact stresses has been presented. Also the comparison of Hertz stresses for Novikov and involute gears has been made.

Bending Strength Calculation Method of Particulate Composite with Size Effect

The mechanical strength of composite functional films is investigated by numerical simulation in this paper. Such functional film is often required bending strength during assembly. It is calculated composites with method to calculate equivalent macroscopic properties such as equivalent inclusion method and homogenization method, but these methods cannot be considered size effect. Therefore, we developed method to evaluate bending strength of particulate composite film by bending calculation of RVE with relative periodic condition. From the results of DOE bending calculations by the developed method, filler size shows a high contribution rate, however the size under 0.1 um doesn't affects the contribution rate.