4.1 INVESTIGATION OF STRUCTURAL BEHAVIOR Investigating how structures behave is an important part of structural design: it provides a basis for ensuring the adequacy and safety of a design, In this section I discuss structural investigation in general. As I do throughout this book. I focus on material relevant to structural design tasks. Purpose of Investigation Most structures exist because they are needed. Any evaluation of a structure thus must begin with an analysis of how effectively the structure meets the usage requirements. Designers must consider the following three factors: Functionality. or the general physical relationships of the structure's form. detail. durability. fire resistance. deformation resistance. and so on. Feasibility. including cost. availability of materials and products. and practicality of construction. Safety. or capacity 10 resist anticipated loads. Means An investigation of a fully defined structure involves the following: 1. Determine the structure's physical being-materials, form, scale. orientation. location. support conditions, and internal character and detail. 2. Determine the demands placed on the structure-that is. loads. 3. Determine the structure's deformation limits. 4. Determine the structure's load response-how it handles internal forces and stresses and significant deformations. 5. Evaluate whether the structure can safely handle the required structural tasks. Investigation may take several forms. You can Visualize graphically the structure's deformation under load. Manipulate mathematical models. Test the structure or a scaled model, measuring its responses to loads. When precise quantitative evaluations are required. use mathematical models based on reliable...
