tailieunhanh - Introduction to MECHANICS of MATERIALS

One of the most fundamental question that an Engineer has to ask him/herself is what is how does it deform, and when does it break. Ultimately, it its the answer to those two questions which would provide us with not only a proper safety assesment of a structure, but also how to properly design it. Ironically, botht he ACI and the AISC codes are based on limit state design, yet practically all design analyses are linear and elastic. On the other hand, the Engineer is often confronted with the task of determining the ultimate load carying capacity of a structure or to assess its progressive. | Draft DRAFT Lecture Notes Introduction to MECHANICS of MATERIALS Fundamentals of Inelastic Analysis VICTOR E. SAOUMA Dept. of Civil Environmental and Architectural Engineering University of Colorado Boulder CO 80309-0428 _ laiL Victor Saouma Mechanics of Materials II Draft iii PREFACE One of the most fundamental question that an Engineer has to ask him herself is what is how does it deform and when does it break. Ultimately it its the answer to those two questions which would provide us with not only a proper safety assesment of a structure but also how to properly design it. Ironically botht he ACI and the AISC codes are based on limit state design yet practically all design analyses are linear and elastic. On the other hand the Engineer is often confronted with the task of determining the ultimate load carying capacity of a structure or to assess its progressive degradation in the ontect of a forensic study or the rehabilitation or life extension of an existing structure . In those particular situations the Engineer should be capable of going beyond the simple linear elastic analysis investigation. Whereas the Finite Element Method has proved to be a very powerful investigative tool its proper and correct usage in the context of non-linear analysis requires a solid and thorough understanding of the fundamentals of Mechanics. Unfortunately this is often forgotten as students rush into ever more advanced FEM classes without a proper solid background in Mechanics. In the humble opinion of the author this understanding is best achieved in two stages. First the student should be exposed to the basic principles of Continuum Mechanics. Detailed coverage of 3D Stress Strain General Principles and Constitutive Relations is essential. In here we shall go from the general to the specific. Then material models should be studied. Plasticity will provide a framework from where to determine the ultimate strength Fracture Mechanics a framework to check both strength and .