Learning Outcomes
With the successful conclusion of the course, the students will be able to: 1) Formulate and solve an elastoplastic problem of loading of a medium and calculate stresses and strains. 2) Select yield criterion depending on the material, formulate the elastoplastic stiffness matrix and the algorithm of the elastoplastic loading. 3) Formulate and solve limit analysis problems for the calculation of failire loads of structures. 4) Describe, fromulate and solve problems of determining the elastoplastic response of a variety of structures (surface and spatial) to static loads, using the finite element method. 5) Αnalyze and solv problems of elastoplastic static analysis of spatial framed structures with the use of specialized software.
Course Content (Syllabus)
Description of the plasticity concept in structures. The physics of plastic deformation. One-dimensional elastoplastic constitutive laws of materials. Tangential and plastic stiffness modulus. Hardening and hardening laws. Hysteresis loops. Yield criteria of ductile and brittle materials and applications. Criteria Tresca, von Mises, Mohr-Coulomb, Drucker-Prager. Constitutive relations of elasticity in matrix notation. Virtual work principles. Prager's stability postulate. Perfect elastoplasticity. Yield surfaces and elastic and plastic strains in three dimensions. Flow rules and plastic potentials. Consistency conditions. Calculation of plastic strains and applications. Plastic dilation. Matrix formulation of the theory and the constitutive equations of elastoplasticity. Incremental formulation and algorithm of the elastoplastic loading. Hardening in three dimensions. Hardening parameters and calibration. Incremental formulation of the constitutive relations for hardening. Loading criterion. Theorems of limit analysis and applications of static and kinematic method. Acceptable field of stresses and displacements. Upper and lower bound theorems. Energy dissipation in the continuum solid and in discontinuities. Applications to foundations and structures like beams and frames. Step by step solution method to analyze flat (2D) frames. Plasticity of brittle materials, rocks and concrete. Constitutive laws and their applications. Uniaxial inelastic constitutive material laws. Synoptic matrix formulation of mathematical relations of the plasticity theory. Elasticity law, yield criteria, hardening law, incremental formulation of constitutive mathematical relations. Plasticization models of finite elements. Numerical methods for solving non-linear static and dynamic problems. Nonlinear seismic analysis methods. Applications to problems of calculating the elastoplastic response of structures with the use of the SAP2000 software package. Also, within the frame of the course, the students elaborate mandatory homework.