Papers by Keyword: Elastic Modulus

Abstract: As a new green building material, straw concrete are introduced about its mechanical properties and characteristics. Mechanical properties test such as prism compressive strength, elastic modulus and Poisson's ratios use standard prismatic blocks. Under different rate of corn straw, cement, sand and fly ash, test gets the full stress-strain curve. Results show that with increase of volume of corn straw, the prism compressive strength reduces significantly. Comparing with natural concrete, elastic modulus of straw concrete can reduces greatly. Poisson’s ratio reduces with increase of volume of corn straw. Fly ash could improve property of the material and replace cement, but excessive replacement will reduce the strength of material.

Abstract: With the rapid development of traffic cause in our country, the operating requirement of driving load factors to pavement structure become higher and higher. The Semi-rigid base asphalt pavement structure exposed some defects and shortcomings, so the study of flexible base asphalt pavement structure is put on the agenda under the circumstances.Based on the research achievements at home and abroad of the existing asphalt pavement structure , choosing different elastic modulus and thickness to calculate and analyze the flexible base by ANSYS, gaining the law and trend of mechanics response (the vertical displacement and tensile stress) about pavement structure for the flexible base pavement of each layer foundation to provide the design reference.

Abstract: Through the test of artificial frozen soil of cretaceous formation soil sample, study the mechanical properties and thermophysical properties of cretaceous formation artificial frozen soil with different soil properties and subzero temperatures. Results indicate that, uniaxial compressive strength of artificial frozen soil of cretaceous formation soil sample linearly increases accompanied with drop in temperature, with identical soil properties and water content; with decreasing temperature, elastic modulus increases and Poisson’s ratio decreases, in the case of the identical soil and ambient temperature; with decreasing temperature specific heat of artificial frozen soil decreases and thermal conductivity increases.

Abstract: The microstructure, texture and elastic modulus of electron beam welding joint in Ti-6Al-4V titanium alloy were investigated by transmission electron microscopy, X-ray diffraction, electron back scattered diffraction and nanoindentation techniques. The α phase was in the majority, and a {0001} <-2110> texture of α phase was observed in the base material. A very weak {11-23} <-1-122> texture of α phase was in the fuse zone. Most of the α grain boundaries in the fuse zone were high-angle boundaries by electron backscattered diffraction, and it also confirmed that the orientations of α phase had a nearly random distribution in the fuse zone. The maximum average elastic modulus value measured by the nanoindentation techniques was in the base material due to the effect of the {0001} <-2110> texture. The average elastic moduli of three different zones in the joint were 134.8±3.5Gpa, 125.5±5.8Gpa and 123.0±4.7Gpa, respectively.

Abstract: Elastic modulus error is the key factor influencing to the forming precision of grinding tool bended in the aspheric processing. The mathematical model of the grinding tool bended has been established through mechanics and the mathematics method, the error formula has been inferred and the influence of elastic modulus error has been analyzed, the calculating example has been given. The result indicates had to confirm material’s elastic modulus value according to the precision request of workpiece in choosing grinding tool material and control it in the certain scope, thus guaranteed the grinding tool the forming precision, further improve the workpiece the face shape precision.

Abstract: Beta titanium alloys are promising biomedical material for their excellent biocompatibility and low elastic modulus. Moderate strength of those materials in beta-annealed condition can be increased by precipitation hardening of alpha phase, but this causes significant increase in elastic modulus. In this study, small additions of Fe and Si are used to increase strength of commercial Ti - 35Nb - 7Zr - 5Ta (TNZT) alloy. Alloys with iron content up to 2% and silicon content up to 1% were manufactured. Elastic properties were investigated by pulse-echo method and flow curves were determined from tensile tests. Modulus of elasticity is increases from initial 60 GPa to 80 GPa due to Fe and Si content. Strength and modulus of elasticity were then related to chemical composition. Yield stress is increased from 450 MPa to 700 MPa thanks to small Fe and Si additions. Fe causes solid solution strengthening exhibited by sharp yield point. (Ti,Zr)₅Si₃ intermetallic particles further increase strength via precipitation hardening. An alloy containing 0.5% Si and 2% Fe showed improved properties for biomedical use.

Abstract: Structural steels have been developed in terms of users needs. Particularly, easy welding is one of the most important factors of steel works that results in submarine structural steel (SM). The SM has become a popular structural steel in building construction in columns and beams proving as good as ordinary structural steels (SS). However, evaluation of fire resistance at H-section made of SM steels was not suggested in terms of boundary conditions. In this paper, to compare the fire resistance of H-section made of SM steels, such as SM 400, SM 490, and SM 520 was tested and analyzed in terms of load carrying capacity at high temperature. The facts showed that as the strength is increased, the reduction ratio of an allowable load is rapid and fixed to fixed boundary condition was more robust than others in high temperatures.

Abstract: The effect of two heat treatment processes on microstructures and tensile behaviors of K465 superalloy was investigated and compared. The results show that hot isostatic pressing (HIP) process partly or completely eliminated the micro-porosity to densify K465 alloy, and can effectively reduce the size of γ′ phase and improve the tensile strength and plasticity of K465 alloy. Electron probe micro-analysis (EPMA) studies revealed that the element segregation ratio was smaller in the HIP process alloy than that in the ordinary process alloy. nanoindentation tests revealed that elastic modulus and the hardness in the interdendrite of K465 alloy for HIP process were higher than that for the ordinary process.

Abstract: The uniaxial compressive tests on frozen loess with different ice content under loading rate of 1.25mm/min at-6°C are carried out to investigate the effects of ice content on the mechanical behavior of ice. The influence of ice content on stress-strain, elastic modulus, strength and failure strain of frozen loess are analyzed based on the experimental data. The results show that strength and failure strain increase with increasing of ice content. The elastic modulus first increase and then decrease with increasing of ice content.

Abstract: With the methods of studying conventional concrete mechanical performance, the influence of concrete performance on the rubber powder replacement rate is investigated. Based on the test data, the relationship of between the elastic modulus and the rubber powder replacement rate is fitted. The results show that the concrete slump decreases with the rubber substitution rate increasing. The compressive strength of the cube of the concrete, the axial compressive strength and the elastic modulus go down in different degree with the increment of the rubber substitution rate.