Papers by Keyword: Steel Plate

Abstract: The Cowper-Symonds relationship is the most common empirical equation used to model the influence of strain rates in steel structures subjected to blast loads. The simplicity of this relationship makes it as the preferred choice due to the minimum number of coefficients used in the equation. However, different coefficients were reported from experimental results where it was found that the coefficients could be influenced by the thickness of the specimens, types of materials and method of testing. Even so, the actual coefficients even for the same type of material such as for mild steel could be differ. It is known that strain rates effect increases the yield strength of steel, and this could reduce the maximum displacement of steel structures such as steel plates subjected to blast loads. This influence could be more significant if the steel plate was stiffened. Therefore, this study investigated the influence of Cowper-Symonds coefficients for steel plates with stiffeners subjected to close-in blast loads. The numerical investigations were performed using finite element software, Abaqus. The target plate was a 0.4 m x 0.4 m plate with 0.002 m of thickness subjected to a 0.012 kg of Plastic Explosive No. 4 (PE4) at 0.04 m stand-off distance. The influenced of stiffeners were investigate first where five stiffeners’ configurations were used and, in each configuration, the stiffeners come with different geometry ratios. Two best stiffened steel plates have been chosen to study the influence of different Cowper-Symonds coefficients. Different coefficient values of dominator, D and hardening coefficients, q was used. The results shows that any possible coefficient combinations of Cowper-Symonds relation are possible to use in predicting response of steel plates subjected to blast loads. From this study, the most ideal stiffened square steel plates for offshore platform could be identified.

Abstract: The heat-induced behavior of strength characteristics demonstrated by a “steel – wood” composite has been studied. The study has revealed the bending strength of steel plates in contact with a wooden bar is maximal if treated by a flame retardant agent containing phosphorous and urea solution.

Abstract: Plate is one of the most common structural elements, which appears in a wide range of applications: steel bridges, blast-resistance door, and armored vehicles. In this paper, the behavior of steel plates under blast loading was studied through numerical approaches using LS DYNA and then the results were compared with the experiment results obtained from existing literatures. The study of a clamped square plate exposed to blast loading in three distinct stand-off distances. Three different methods of modeling blast loading were used, namely: empirical blast method, arbitrary Lagrangian Eulerian (ALE) method, and coupling of Lagrangian and Eulerian method. The empirical blast method was deployed by using key card *LOAD_BLAST in LS-DYNA. In ALE method, Langrangian and Eulerian solution were combined in the same model and the fluid-structure interaction (FSI) handled by coupling algorithm. In coupling method, the engineering load blast in LS-DYNA (*LOAD_BLAST_ENHANCED) was coupled with the ALE solver. In terms of central deflection and computational time, the coupling method appeared to be the best method which is very time-effective and showed a good correlation with the experiment data.

Abstract: Existing experimental observations have shown that the application of externally bonded reinforcement (steel plate, FRP laminate, overlay, etc.) to strengthen RC structures can lead to brittle failures involving debonding of the external reinforcement before the design load is reached with classical failure modes. The design approach to determine the strengthening material and its area should avoid these premature failures. In this study, an analytical model developed for the overlay strengthening by the authors is firstly proved to be applicable for the steel plate or FRP laminate strengthening by comparing the analytical and experimental failure load as well as the failure mode of the strengthened beams reported in the literature. Then the main parameters involved in the process of concrete cover separation are identified and a simple criterion is proposed for prediction of premature failure.

Abstract: In this paper, on the basis of specimen model size mentioned in steel reinforced concrete coupling beam stress performance research, using the ANSYS finite element software about coupling beam specimens with different steel plates for one-off monotonic loading. Through the comparative analysis of simulation results, to explore the impact of different steel plate forms on shear capacity and ductility of coupling beams, etc .

Abstract: The purpose of this study is to investigate shear performance of RC beams strengthened with combined CFRP and steel plates. Fourteen beams were tested to shear failure under simply supported four-point loading conditions. The variables of this investigation included strengthening technique, shear span to depth ratio, percentage of CFRP, percentage of steel plate, CFRP and steel plate orientation, CFRP and steel plate wrapping type. The results show that the simultaneous application of CFRP sheets and steel plate greatly increases the shear resistance of RC beams. The steel plates improve the bond behavior of CFRP sheets. A design formula is proposed to calculate the shear resistance of the beams strengthened with combined CFRP sheets and steel plates. The predictions agree well with the test results.

Abstract: This paper introduces the study and production on steel plate of Grade E550 in60mm thick by Thermo-mechanical processing (TMCP) and tempering for offshoreinfrastructure purpose. The steel plate obtained high strength and goodtoughness in both the base materials and the weld joints. Microstructure and precipitation characteristicswere examined in the plate is comprised of bainite with a small amount ofpre-eutectoid ferrite. Parallel arranged lath bainite characterizes thebainitic structure with high density of dislocations and precipitates. Carbides M_xC_y averaging 200nm indimension and MC type Carbonitrides in several nano to a dozen nano carbidesdistribute in the bainite ferrite and the bainte lath interfaces. Compatiblemechanical properties were achieved at welded joint. Microstructures were analysed in the welding heataffected zone (HAZ).

Abstract: Repair of reinforced concrete beam with externally bonded steel plate or fibre reinforced polymer (FRP) laminate is becoming both environmentally and economically preferable rather than replacement of deficient beam. The well known advantages of external reinforcement over other methods include; low cost, ease of maintenance and the ability to strengthen part of the structure while it is still in use. The disadvantage of this method, however, is the premature debonding of the externally bonded strips which is brittle and undesired mode of failure. It is also known that debonding of the externally bonded steel plates prevents the reinforced concrete (RC) beam from reaching its full strengthening capacity. The aim of this study was to increase the scientific understanding on the behaviour of damaged reinforced concrete beams strengthened and/or retrofitted for shear using vertical steel plate fixed with adhesive and steel connectors to eliminate or delay debonding failure. Four reinforced concrete beam specimens were prepared to investigate the effects of connectors in preventing or delaying premature debonding of shear strips to restore the capacities of fully damaged beams. Three damaged beams have been repaired and strengthened with steel plates and loaded monotonically up to the maximum load capacities in order to define load–deflection relationship. It is concluded that the repairing of severely shear-damaged RC beams with steel plates by using steel and adhesive connectors can fully restore the original shear capacities of the beams.

Abstract: Water gate is one of important equipments for arbitrating water supply and maintaining safety of dam. Water gate is made of high tensile strength of steel plate, this kind of steel plate used as constructional material of water gate is weighed for the economical consideration. Steel plate must be cut, welded and rivet to manufacture water gate. Thus, there are some crevices, induced by the defects of material, bad construction, seismic excitation and errors of size, on water gate. This phenomena causes stress concentration, induced high crack increase rate, affect the safety and usage of water gate. In this research, digital image correlation method is developed to measure the mechanics behavior of single steel plate and bi-steel plate with crevices under tension force according to the characteristics of water gate filed test. The test and analysis results of laboratory test reveal that this digital image correlation method can easily indentify the corrosion point on the steel plate. Otherwise, the crack variation of crack tip of steel plate-single steel plate and bi-material steel plate under loadings can be easily identified by the laboratory test.

Abstract: Fiber Reinforced Polymer (FRP) strengthening of structures has been gaining increasing interest, traditionally in application with concrete structures, and more recently in application with steel structures. Because of their unique blend of properties, composites reinforced with high performance fibers find use in many structural applications. This paper defines the effect of FRP layers on behaviour of steel plate. In this regard, some models are selected and tested by rigid frame and actuator. The experimental model is connected to a rigid frame. The FRP layer acts similar to a lateral support for the steel plate, and possesses the intelligent behavior (specified control for establishing of flexural line and further leaning towards post buckling condition), meaning that the FRP layer can lead the local flexural deflection towards the total flexure of the steel plate and effectively contributes more in resisting the shear stresses and extension of post flexure lines in steel plate and formation of composite plate. This is due to involvement of more area of steel plate to resisting of the imposed stresses. Result shows, the FRP layers would increase the stiffness, energy absorption, shear capacity and will be decreasing the ductility of steel plate as compared with composited steel plate with other materials as reinforcement concrete.