Papers by Keyword: Shear

Abstract: In the modern building construction, different size of openings are provided in the web of reinforced concrete (RC) deep beams to accommodate utility pipes and ducts of essential services such as electricity cable, telephone network and air-conditioning network. However, accommodation of such openings caused reduction in beam strength, stiffness and caused excessive cracking and deflection. Many investigations were conducted to study the behaviour of openings in beams and relevant strengthening options to reinstate the lost capacity. One of the strengthening options considered lamination of fiber reinforced polymer (FRP) sheets due to its superior properties such as high tensile strength and stiffness, high resistance to corrosion, excellent fatigue performance and good resistance to chemical attack. FRP lamination has been widely accepted by the research community and practicing engineers in the construction industry as the material for strengthening and rehabilitation of common problems. However, quite limited literatures contained the use of FRP to strengthen RC deep beams with openings. This paper discussed the review of eleven different articles contained study of RC deep beams with openings together with effects of strengthening using FRP sheets. The outcome of this review paper outlined the way forward and future research focus in this area.

Abstract: In this study, the effect of bond thickness upon shear strength and fracture toughness of epoxy adhesively bonded joint with dissimilar adherents was addressed. The bond thickness, t between the adherents was controlled to be ranged between 0.1 mm and 1.2 mm. Finite element analyses were also executed by commercial ANSYS 11 code to investigate the stress distributions within the adhesive layer of adhesive joint. As a result, shear strength of adhesive joint reduces with increasing bond thickness. The strength of shear adhesive joint was also depended on elastic modulus of adherent. Moreover, the failure of dissimilar adherents bonded shear joint originated at a location with critical stress-y which was the interface corner of ALYH75/epoxy. In the case of shear adhesive joint with an interface crack, the fracture also occurred at the ALYH75/epoxy interface even in the steel-adhesive-aluminum (SEA) specimens. Fracture toughness, Jc of aluminum-adhesive-steel (AES) joints was similar to those of SES and demonstrates strong dependency upon bond thickness. Furthermore, the interface crack in SEA specimen has relatively large fracture resistance if compared to those in AES specimen. Finally, Kc fracture criterion was found to be appropriate for shear adhesive joints associated with adhesive fracture.

Abstract: This paper focuses on the assessment of the shear strength prediction established in the brazilian concrete code, NBR6118/2007[1], for reinforced concrete beams without web reinforcement. The values obtained by using the brazilian code equation are compared with a significant number of available experimental data and with those predicted by the expressions of other national and international codes, such as CEB-FIP MC90[2] and ACI-318/11[3]. The brazilian concrete code regarding shear capacity of reinforced concrete elements are explicitly assumed to be valid only for concrete strengths up to 50 MPa. It is shown that the code equation may be unconservative in a large number of cases. This discrepancy increases with increasing concrete strength, decreasing longitudinal reinforcement ratio and increasing beam depth.

Abstract: This work examines the processing and some mechanical properties of copper-electroplated graphite compacts. Shear and wear tests were conducted. Natural graphite (NG) flakes were compressed to make graphite compacts. No polymer binder was added in the compact. For reinforcing and preventing the NG particles from peeling off, a copper layer was electroplated on the compact. The density of green graphite compact approached a limit when the forming pressure was higher than 100 MPa. The results indicated that the shear strengths increase 150% and the wear resistance is improved more than ten times because of the copper layer. The induced damage mechanisms were examined, and the influence of the copper layer on the damage is discussed.

Abstract: This work deals with the time-dependent creasing characteristics of coated paperboard. The correlation between the bending strength (resistance) and time-dependent problems on the actual processing phenomenon has not been sufficiently discussed in the past. It is difficult to estimate various time-dependent responses from the initial strength of the creased part, such as the maximum bending moment and the initial gradient of bending moment. In this study, therefore, a prototype testing apparatus has been applied to investigate about the dynamic relaxation of bending moment. In order to reveal the relaxation characteristics of the bending resistance during the folding motion from an initial position up to various tracking angles, a white-coated paperboard of 0.3 mm thickness was scored with a creasing rule and a grooved counter face plate under a specified feed velocity, and then the bending test was carried out by varying the tracking angle. Through this work, the followings were obtained: (1) The relaxation of the bending moment was characterized by an exponential coefficient which was independent to the nominal shear strain and the tracking angle. (2) The relaxation depends on the rubbering condition.

Abstract: The degradation of laminated glass as a result of increased temperature has become one of the important problem of reconstructions and designs of new glass structures, for instance high-rise buildings that are exposed to the impacts of an intensive heating caused e. g. by sunshine. The temperatures during heating can reach very high values, commonly from 60 to 70 °C. The effect of heating was simulated using the thermal chamber where the glass panes with the size of 120 x 1100 mm were heated. The deformation course under the increase of temperature was continually monitored by a measuring unit. In total six types of foils joining particular layers of glass were examined. In this paper the experimentally gained results are compared with a numeric computer analysis and the particular kinds of interlayers are evaluated using the loss of shear interaction.

Abstract: This article introduced the principle of hydraulic system for billet continuous casting shear in Ma-steel. Analyzed the problem that the hydraulic system flow was not enough to meet manufacture need during commissioning. put forward the solution that accumulators group was made use to add hydraulic system flow according to manufacture actual fact,resolved the practical problem and obtained the satisfactory effect.

Abstract: The auto-rickshaw has become a predictable part of the everyday lives of Indian city-dwellers. Although this popular means of public transport provides relatively discounted and efficient transportation, the auto-rickshaw is a key source of soot that causes particulate air pollution. These soot emissions infringe the natural cycles of the atmosphere other than their more overt effects on human health. Consequently, their entrapment becomes vital. Though most particulate filters provide a rather good efficiency, once clogged an undesired back pressure may lead to engine and/ or filter failure. Through this study a method is proposed to overcome such impenetrability. Once the particles are confined to narrower streams, smaller filters may be used which even if clogged will allow the easy passage of the exhaust gases out of the exhaust pipe. The most immediate outcome of this research is that the CFD simulations suggest inexpensive design alterations in the diesel particulate filter which can be fabricated easily. With government subsidies this component can be mass manufactured for use in India and other Asian countries where auto-rickshaws are widely used.

Abstract: The bonded interface between FRP plate and the hydraulic concrete is a key part while reinforcing the hydraulic concrete structure with FRP plate. The bond property of the interface directly decides the results of structural reinforcement. In most of the external loading conditions, this interface is under the shear stress state. Therefore, accurate measurement and analysis of interfacial shear stress distribution is the guarantee of FRP reinforced hydraulic concrete structure the premise of success. Focusing on the shear-resisting bonding strength of FRP-concrete interface, this paper improved the ASTM D905 standard shear sample and carried out numerical simulation of shear test to the bonded interface of FRP-reinforced hydraulic concrete structure by adopting the bi-dimensional finite element method, and conducted parameter analysis of the influence factors (elasticity modulus of FRP and concrete, shear modulus and thickness, etc) of shear stress on the FRP-concrete bonded interface and finally the distribution characteristics of shear stress on the bonded interface were obtained. This paper mainly discussed the influence rules of stress concentration to the distribution of shear stress on the bonded interface, which provides theoretical guidance and direction to the shear-resisting bonding strength test in the next step as well as technical support to the processing of FRP-strengthened hydraulic concrete bonded interface.

Abstract: The shear interaction of laminated glass belongs to the essential characteristics of this material. The impact of the increased temperature on deformation properties was tested within investigation of basic mechanical properties of laminated glass panes. The specimens of laminated glass with the size of 120 x 1100 mm loaded by four-point bending load were exposed to the effect of the gradually increasing temperature up to approximately 65 °C in a thermal chamber. The progress of the deformation was continuously monitored by a measuring device during both temperature rise and subsequent cooling. Four kinds of interlayers were tested in total. In this paper the obtained experimental results are compared to numerical FE analysis and also the degree of an interaction of particular interlayer is evaluated.