|
|
Reliability assessment of steel tubes considering due to fracture
Marek, Pavel ; Korouš, Jan ; Bielak, O.
Cracks are most dangerous defects which can be found in real structures, Prediction of the crack instability is influenced by many factors of random nature. To take into account these random variables, SBRA approach can be adopted. The paper show how the probabilistic assessment can be used for calculation of fracture probability in a cracked pipe, as random variables, material properties and crack depth were assumed. The assessment resulted in fracture probability which can be compared with a target value
|
|
| |
|
| |
|
| |
|
|
Notes on approximation of stochastic programming problem
Šmíd, Martin
In stochastic optimization problems, expectation of random function is often being minimized. Since the expectation can rarely be evaluated exactly an approximation has to be done. In the present paper, three types of approximation are dealt with: discretization, Monte Carlo and Quasi Monte Carlo. Convergence rate of the approximation error is evaluated and some upper bounds of the error are given.
|
|
|
Reference functions and values
Marek, Pavel
The current structural reliability assessment criteria (corresponding to the prescriptive Limit States Design concept such as Eurocode and AISC-LRFD) are expressed by comparing the specified maximum load effects and minimum specified resistance. In the qualitatively different gradually developed probabilistic reliability assessment procedures(applicable in codes) clear definitions of the „reference“ functions and values applied in the calculation of the probability of failure must be specified and adequate target probabilities must be given considering tolerable risk, economical requirements and some other measures.
|
|
|
Atomistické simulace uspořádávání v niklových slitinách pod vlivem mechanického napětí
Buršík, Jiří
Systems containing up to six alloing elements typical of advanced Ni-based superalloys were modelled.their ordering was simulated at atomic level using a Monte Carlo approach with púeriodic boundary conditions and Kawasaki dynamics.molecular dynamics routines were embedded into standard kinetic Ising model to account for relaxing of local atomic positions.Straining computer experiments show that elastic parameters and bulk modulus undergo comparatively large changes at the beginning of ordering process.
|
|
| |
|
| |
|
| |
guest ::
