Non-linear analysis of disposable knee bracing

Abstract An approximate method is presented that can be used to determine the non-linear behaviour of a new structural bracing system called the ‘Disposable Knee Bracing’. In this framing system, a special form of diagonal brace connected to a knee element instead of beam-column joint, is investigated. The diagonal element provides lateral stiffness during moderate earthquakes. However, the knee element is designed to have three plastic joints for dissipation of the energy caused by strong earthquake. This article demonstrates the transformation of a complex problem into a new, practical set of design charts and graphs. First, by studying of the elastic behaviour of the system, a suitable shape and angle for diagonal-knee bracing is proposed. Then, by use of the main graphs and charts designed accordingly, the dynamic response of this model is properly investigated. Finally, the correctness of the results is ascertained, using an example problem.