Papers by Keyword: Shear Strength

Abstract: This study was undertaken to investigate some specific problems that limit a safe design and construction of structures on problematic soils. An experimental study was carried out to examine the influence of loading rate and moisture content on shear strength of organic soil. Influece of moisture content on interface friction between organic soil and structural materials was also attempted. A commonly used soil in Iraq was prepared at varying moisture contents of 39%, 57% and 75%. The experimental results showed that the increase in water content will decrease the shear stress and the internal friction angle. An increase of the shearing rate was found to decrease the shear stress and internal friction angle for all percetanges of water contents. Further, direct shear tests were carried out to detect the interface shear stress behavior between organic soil and structural materials. The results revealed that the increase in water content was shown to have significant negetavie effects on the interface internal friction and angle shear strength.

Abstract: The main problem in infrastructure development at the soft clay was its bearing capacity therefore it needs to be improved. In this research, the improvement method was carried out by modeling in small scale of preloading and heat induction combination. Location of soft clay sampling was in Takalar, Indonesia. The purpose of this study was to investigate the change of the shear strength of soft soil corresponding with heat induction at the radial zone. The shear strength was obtained by vane shear test and compressive strength from unconfined compressive test (UCT). The heat applied ranging from 100^o C, 200^o C, 300^o C, and 400^o C with static preloading load 0.20 kg/cm². The strengths of the soil in radial zones have been tested at R0, R1, and R2. At lowest temperature 100° at R0 the compressive strength was 0.203 kg/cm2, at highest temperature 400° at R0 the compressive strength 0.467 kg/cm2, there was a significant increasing of compressive strength value with the change of temperature. At the highest temperature 400⁰ the shear strength from vane shear tests resulting at R0 0.240 kg/cm², R1 of 0.128 kg/cm², R2 of 0.077 kg/cm². At the lowest temperature of 100^o C shows R0 at 0.116 kg/cm², R1 at 0.070 kg/cm², R3 of 0.046 kg/cm². The results show a tendency of declining strength value as the soil farther away from center of heat induction. The experimental result from this model produces strength that can be used as a parameter of the foundation model on soft soil.

Abstract: The hot rolled single sided stainless steel clad plate of 316L stainless steel and Q345C steel was carried out in a hot rolling line by the technology of “electron beam vacuum welding and hot rolling”. High quality single sided stainless steel clad plates were produced by asymmetrical compound billet and asymmetrically rolling. The productions of stainless steel clad plate have reached the requirements of GB / T 8165-2008. The interface shear strength is greater than 320 MPa. The yield strength is greater than370 MPa. The tensile strength is greater than 520 MPa. The elongation is greater than 30%, A good metallurgical bonding between stainless steel and carbon steel was achieved. The bonding rate reached 100%. The composite interface is straight and perfect. The pilot production in the study has laid down the certain basis for the production of the single-side dissimilar-material composite board.

Abstract: The effects of bismuth content on the microstructure, shear strength and thermal properties of Sn-0.7Cu-0.05Ni solder joints were investigated. Adding 2 wt% elemental Bi to Sn-0.7Cu-0.05Ni solder joints reduced peak temperature by about 6.7 °C, increased pasty range by 4.2 °C and raised undercooling by 3.1 °C. The microstructure of the interfacial layer between solder and Cu substrate was composed of (Cu,Ni)₆Sn₅ and (Cu,Ni)₃Sn intermetallic compounds (IMCs). The solder joint included a phase of SnBi and Cu₆Sn₅ IMCs. The addition of elemental Bi increased shear strength and suppressed the growth of IMCs in the interfacial layer of the solder joints.

Abstract: The subject of the article is to give a full analysis of the cascade type layouts in elements strengthening design in bending by gluing the fiber reinforced polymer (FRP) materials on their surfaces’ applicability and effectiveness. The research objectives are the substantiation elements cascade method application reinforcement with adhesive joints. Materials and methods are revealed in a few variants of FRP-reinforcement with application of FEM simulation. A number of diagrams and tables represent the results. The results are defined in the cost-effective efficient method presentation of the bent elements strengthening to increase their bearing capacity reserves, the features of the bonded joint behavior, the equations and formulae for the glue joint analysis and design. Conclusions are formulated in depicting the “cascade” reflects, the features of the proposed strengthening design, the base element unloading, which is gradual with each successive element attached. The design examples are oriented on the adhesive joints’ application possibility analysis of attaching the FRP elements. The results suggest the effective use possibility of the adhesive joints to strengthen rather stiff, including steel, elements in bending. The cascade method eliminates the indispensability of highly expensive high-strength materials, thereby reducing the reinforcement structures cost.

Abstract: Earthen constructions are spread worldwide, not only as architectural heritage but also as new buildings, in which a total of around one fourth of the global population is estimated to live in. Among the different raw earth techniques, rammed earth was widely used to build vernacular dwellings in different regions. Despite the raising awareness for the high seismic hazard, recognized seismic vulnerability and high seismic exposure associated with earthen structures, the reduction of their seismic risk has been a topic insufficiently addressed. In general, the seismic vulnerability of rammed earth structures is due to poor connections between structural elements (walls and floors), high self-weight and low strength of the material. Hence, a TRM-based strengthening technique is proposed to improve their seismic capacity. To estimate the enhancement of the in-plane performance achieved with the TRM, an experimental program was conducted. Rammed earth wallets were tested under diagonal compression considering their unstrengthened and strengthened condition. The TRM strengthening was performed by embedding a glass fibre mesh (GRE) or a nylon mesh (NRE) in a compatible earth-based mortar. In general, the proposed TRM-based strengthening seems to improve the shear behaviour of rammed earth by enhancing the shear strength and promoting stress distribution after cracking, while no significant influence on the shear modulus of rammed earth seems to occur.

Abstract: Use of high strength concrete require reliable predictions of correlations of compressive strength with tensile strength or splitting strength. Analysis of correlation between tensile strength of concrete and compressive strength, based on experimental results, is shown in this paper. It is proposed new simple correlation. Regression analysis that use, is based on the results of the experimental researches of compressive strength and splitting tensile strength, at specimens of high strength concrete. Comparative analysis of test results, gained for high strength concrete and normal strength concrete is performed. Analysis comprises the results of the experimental research of deep beams subjected to shear. Stresses measured on surfaces of high strength concrete beams subjected to shear and level of stresses that induce inclined cracks in concrete are applied. Relationship between concrete compressive strength and shear cracking stresses is studied, too. Experimental research was done at pairs of the beams made of concrete with high compressive strength and normal compressive strength. Estimation of validation of relations prescribed by the design codes for high strength concrete has performed.

Abstract: Aluminum foams/aluminum plate was transient liquid phase diffusion bonded with Cu/Al/Cu composite interlayer, then the investigation on joint microstructure, element diffusion and joint strength was conducted at 565°C. The results showed that, there was a significant grain boundary penetration phenomenon near the interface and it was more seriously at the side of aluminum foams. The XRD results showed indicated that the main phases near the interface were α-Al, CuAl₂, AlCu, Al₄Cu₉, Al₂O₃. By EDS line scanning, it indicated that the diffusion behavior of elements was different at three regions, compared with the edge region, the interface of the central region was better and the depth of element diffusion is larger, at the pore region, the liquefaction of interlayer was not successfully and the morphology was lamellar. Mechanical properties test showed that the largest shear strength of joint was 4.61 MPa when the duration was 40 min. Key words: Aluminum foams; transient liquid phase bonding; microstructure; element diffusion; shear strength

Abstract: SS400/SUS304 steels lap joint was applied in various industries due to flexible andbeneficial properties of these dissimilar metals joint. Therefore, an investigation for optimization ofa gas metal arc welding (GMAW) for producing the dissimilar metal lap joint should be conductedfor advancing the manufacturing industries. This research applied GMAW with various currents andspeeds to weld SS400/SUS304 lap joint and studied the relationship between the parameters andresuted joint properties. The experiment showed that an increase in the wedling current and a decreasein the welding speed affected to increase the fracture strength, the displacement of the lap joint, andthe joint hardness due to high combination of the materials at the joint interface. The uncombinedmaterials at the carbon steel/weld metal interface had the different hardness and resulted to initiatethe crack that then was propergated until the joint was broken. The weld metal showed the formationof the finer and smaller dendrite structure with increasing the welding current and decreasing thewelding speed.

Abstract: The porous plate is the key part for distributing gas in the fluidized bed, which is subjected pressure, tension and shear from flowing gas and material during work. The porous plate is required to have good mechanical properties. The Monel porous plate was prepared by the powder metallurgy process in this paper. Meanwhile, in order to obtain the status of compressive resistance and shear, the compressive property and the shear property were studied. The results showed that the compressive resistance yield strength was 143MPa and elastic modulus was 18.1GPa at the edge of porous plate. In the central part, the compressive resistance yield strength was 67 MPa, elastic modulus was 8.2GPa and elastic strain range was 3 %.The minimum shear strength was 116 MPa in edge and 87 MPa in the central.