875336 Reliability and safety evaluation - Probabilistic methods for existing structures


Type
Lecture and exercise
Semester hours
3
Lecturer (assistant)
Strauss, Alfred , Pukl, Radomir , Novak, Drahomir
Organisation
Offered in
Sommersemester 2022
Languages of instruction
Englisch

Content

• Reliability theory, overview
• Monte Carlo - type simulation techniques, importance sampling
• Stochastic methods in structural engineering and nonlinear analysis,
• Approximation techniques, FORM, SORM, response surface methods
• Latin hypercube sampling, statistical correlation
• Random fields and stochastic finite elements
Computer lab: Reliability software FREET, illustrative examples, practical exercise

• Constitutive laws for concrete and other quasibrittle materials
• Nonlinear fracture mechanics of concrete
• Strain localization, spurious mesh sensitivity, localization limiters
• Crack band model, nonlocal continuum mechanics
• Stochastic mechanics - reliability assessment of reinforced concrete structures
• Deterministic and statistical size effect
• Parameters identification using statistical virtual simulation and artificial neural networks
Computer lab: Software ATENA, SARA, illustrative examples, practical exercise

Previous knowledge expected



Objective (expected results of study and acquired competences)

Part I: Reliability
Methods for efficient statistical, sensitivity and reliability assessment will be presented. The attention is given to the techniques which are developed for an analysis of computationally intensive problems which is typical for a nonlinear FEM analysis. The lecture will present the possibility of "randomization" of computationally intensive problems in the sense of the Monte Carlo type simulation. Latin hypercube sampling is used, in order to keep the number of required simulations at an acceptable level. The technique is used for both random variables and random field´s levels. Sensitivity analysis is based on nonparametric rank-order correlation coefficients. Statistical correlation is imposed by the stochastic optimization technique - the simulated annealing. The multipurpose software FReET (http://www.freet.cz) will be presented too.

Part II: Nonlinear analysis of concrete structures
A probabilistic approach to nonlinear fracture mechanics analysis of concrete structures will be presented. Nonlinear finite element software ATENA is used for realistic simulation of damage and failure in concrete and reinforced concrete structures. It is based on advanced material models with damage concept, smeared crack approach and crack band theory with fracture energy-related softening. The programs ATENA and FREET are integrated into SARA shell in order to randomize the fracture analysis of engineering structures. Efficient techniques of both nonlinear numerical analysis of concrete structures and stochastic simulation methods of Monte Carlo type were combined in order to offer an advanced tool for assessment of realistic behavior of concrete structures and
You can find more details like the schedule or information about exams on the course-page in BOKUonline.