Lightweight structures comprise of actual pieces or segments that give the crucial ability to function while weighing less than other possibilities as well. The aerospace industry invented this ...particular branch of expertise, which is sometimes referred to as lightweight engineering or lightweight construction. This paper focuses on how lightweight structures are developed and applied in the field of structural engineering which is essential to achieving the high standards and breakthroughs of modern science. Comparison is made depending on different types of lightweight materials such as titanium alloys, shape memory alloys, magnesium, aluminum alloys, and wood composites, benefits, and applications of each type of material are discussed. Recent technologies and innovations in the field of lightweight design are performed including deployable and morphing structures, 3D printing, embedded sensors and actuators, and advanced joining technologies. Moreover, research is also being done on these structure types of evolution, uses, and significance, as well as their design techniques and innovations. Truss, tensegrity, pantographic, cable, origami, and sandwich structures are identified by explaining their properties and working mechanisms. The usage of several lightweight structures in the fields of aerospace, robotics, civil engineering, architecture, automotive, and biomedicine is examined in this paper. Additionally, the comparison is made between the application of tensegrity, truss, pantographic, and sandwich structures in aircraft applications in detail, while the importance of shape morphing and deploying of pantographic and origami structures is explained in the field of aerospace and robotics. In addition, different types of bridge structures and architecture are mentioned according to applications of suspension cables, stayed cables truss structures, and tensegrity techniques. Furthermore, the paper covers the improvement of computational and numerical techniques in the analysis and design of lightweight structures including the force method, dynamic relaxation method, and finite element method (FEM), trends in optimization techniques and their applications are included mentioned sequential quadratic programming (SQP) and interior point optimization, with applications on different types of lightweight structures. Also, perspectives and future directions of lightweight design through sustainability and smart construction are taken into account, importance of lightweight design in the form of environment and innovation is clearly supported.
The defective structures must be retrofitted to resist the effects of earthquakes due to the potential risks connected with reinforced concrete structures designed in many parts of the world in ...accordance with codes that are now proven to guarantee insufficient safety against seismic loads. Typically, shear walls or steel bracing are utilized to boost the seismic strength of framed structures. This paper discusses the possibility of using braces in two different conditions, the first one is in retrofitting already constructed structures that don’t have sufficient strength against seismic loading, and the second one is the possibility of using braces instead of shear walls in designing non constructed reinforced concrete structures for economical purposes. Different bracing systems in different locations compared with reinforced concrete shear walls in affecting the structural properties of the 10-story square building. Using bracing in the interior frames of buildings was also considered. The results show that different bracing systems have different responses for structural properties such as story displacement, base shear and fundamental time period. The results are significant for detecting the best bracing system to use instead of shear walls reflecting for the two mentioned scenarios as well as considering their locations on the building.
