International Journal of Scientific & Engineering Research, Volume 12, Issue 10, October 2021 ISSN 2229-5518 IJSER © 2017 http://www.ijser.org BEHAVIOR OF DOUBLE SKIN FLAT COMPOSITE WALL UNDER LATERAL LOAD Cezar Dasi Abstract— Shear walls are the primary lateral load-carrying elements in tall buildings. The composite shear walls with double steel plates and filled concrete are composed of two steel plates with studs inside, they were developed to enlarge the building space, and to delay the appearance of cracks by using the steel plates as formwork. Double skin composite wall panels can offer high strength and robustness while improving the convenience of construction, with great potential for application in nuclear power plants. This paper studied the behavior of double skin flat composite wall with several different plate thickness and stiffeners shape (L, T) The models subjected to axial and wind load to present more information to the structural designers and to improve the DSFCW to be used widely in engineering construction. The DSFCW like any other structure element need to be improved and strengthen when is subjected to any type of load so it's important to find the optimum strengthening technique. Index Terms— Structure Engineering, Civil Engineering, Composite Walls, Stiffeners, Windload, DSFCW, Simulation FEM. —————————— ◆ —————————— 1 INTRODUCTION He composite steel plate shear walls are executively sim- ple, and there is no particular complexity in the system, thus engineers, technicians and technical workers with their technical knowledge and without having to learn new skills can perform the system. Work precision is at the level of conventional precision in steel structures and with that con- sideration, there will result much higher executive safety fac- tor compared with the other systems. Due to its simplicity and the possibility of constitution in a factory and installed on the site, system executive speed is high and the enforcement costs will be reduced significantly The composite steel plate walls structure usage has been in- creasing especially due to their extremely low weight that leads to reduction in the total weight and fuel consumption, high flexural and transverse shear stiffness, and corrosion re- sistance (ASM Handbook 2004). The composite steel walls consist of two steel plates with studs inside and two steel tubes with concrete filled aside. The steel plates can be used as the formworks for the con- crete filler during construction and they can also delay the appearance of concrete cracks. Steel plate-concrete composite walls are lately developed forms of structural walls compared to the traditional reinforced concrete (RC) wall. The double-skinned flat steel sheets infill with con- crete composite wall (DFSCW) have been used as load resist- ing systems in building structures in the past, especially in United States since 1970's when initially they were used for seismic retrofit of low and medium-rise existing hospitals and other structure. The lateral and gravity load-resisting system consists of reinforced concrete walls and reinforced concrete slabs. Composite steel walls are the main vertical structural elements with a dual role of resisting both the gravity and lat- eral loads (Edificios Chilenos de Hormigón Armado, 2002. Ed. ICH, Chile). 2 PARAMETRIC OF STUDIES The study suggested to investigate the behavior of double skin flat composite wall plate thickness of 4mm, 6mm, 8mm, each steel plate will enhance by adding different stiffeners shape of L and T. The models will be subjected to axial and wind load to present more information to the structural designers and to improve the DSFCW to be used widely in engineering con- struction. Moreover, the DSFCW like any other structure ele- ment need to be improved and strengthen when is subjected to any type of load so it's important to find the optimum strengthening technique. 2.1 AXIAL LOAD RESULTS To Study the effect of steel plates thickness and several shapes of stiffeners, several specimens will be modeled to in- sure that the result is satisfied with the elements. Six speci- mens with different plate thickness of 4mm, 6mm, 8mm each steel plate fabricated with two different shapes of stiffeners DSFCW – (L, T) as it showing below in table 4.1 the specimens will be compared in terms of displacement. Figure 4.1 below showing the results of axial load. Figure 4.1 T