Ahlul Bayt International UniversityConcepts and Functions in the Building Engineering2120260201Performance of Friction Dampers and Rotational Friction Dampers1672632310.22034/IJSCEBG.2025.176319ENMehdiShalchiAssistant Professor, Faculty of Engineering, Ahlul Bayt (a.s.) International University0000-0003-4601-1082Journal Article20250713Friction Dampers (Frictional Dampers) operate based on the principles of a Coulomb damper or a friction pad that converts kinetic energy into heat through friction. Essentially, friction dampers help a structure to elastically vibrate and dissipate seismic energy in a reversible manner.In recent years, research has shown that the use of friction dampers is one of the most effective methods for absorbing and dissipating earthquake energy. They are also among the simplest types of energy dissipation devices used in structures. The mechanism and operation of these friction dampers involve converting the kinetic energy generated by an earthquake into thermal energy through the friction between the damper plates. During this process, the energy is dissipated, and the resulting hysteresis loops represent the energy dissipation capacity of the system.https://cfbejournal.abu.ac.ir/article_726323_fe1030310b19379edd30295544235e0b.pdfAhlul Bayt International UniversityConcepts and Functions in the Building Engineering2120260201Economic and regulatory analysis of the use of three options: welding, bolting, or a combination thereof in steel structure connections (In residential, special and minor buildings)110724434ENEbrahemAhadiJournal Article20250520<span style="font-family: 'Times New Roman',serif; mso-fareast-font-family: Calibri; mso-bidi-font-family: 'B Nazanin'; mso-bidi-language: FA;">Steel structure connections act as key factors in the overall performance of structures, significantly impacting project cost, construction time, strength, and safety. Selecting the appropriate connection method—whether welded bolted or a combination thereof—depends on various factors, including the project type, environmental conditions, regulatory requirements, and technical specifications. This paper presents an economic and regulatory analysis of these three options. By examining the advantages and disadvantages of each method across different structural contexts, it provides recommendations for selecting the optimal connection method. The results indicate that welding is the optimal choice for complex projects subject to heavy loading, bolting is best suited for simple and cost-effective projects, and a combination of welding and bolting is ideal for specialized structures. Making the correct selection can significantly influence project efficiency, cost, and construction timelines.</span>https://cfbejournal.abu.ac.ir/article_724434_3bb80e373e651912bdcb35021218b8f0.pdf