|
|
Prediction of slow crack growth in polymer pressure pipes
Luky, Robin ; Knésl, Zdeněk (referee) ; Hutař, Pavel (advisor)
A new methodology of polymer pipe lifetime estimation taking into account residual stresses is described in this thesis. Engineering equations derived based on numerical simulations of a hydrostatic pressure test are proposed. Residual lifetime calculations were performed for different loading conditions using experimental data of a creep crack propagation in studied material and stress distribution in the pipe wall. The effects which significantly influence lifetime estimation were quantified with special focus on residual stresses.
|
|
|
Modelling of vibration of dynamic systems with n-degrees of freedom
Luky, Robin ; Hadaš, Zdeněk (referee) ; Dušek, Daniel (advisor)
This Bachelor’s thesis deals with vibration of dynamic systems with luminous parameters with n-degrees of freedom. It features decision procedures of free-running undamped systems, exciting undamped systems, exciting damped systems and their natural shapes, natural frequency and gain-frequency characteristic. At the end of this Bachelor thesis there is an analysis of dynamic damper. The analysis is conducted in agreement with the theoretical procedures listed above.
|
|
|
Prediction of slow crack growth in polymer pressure pipes
Luky, Robin ; Knésl, Zdeněk (referee) ; Hutař, Pavel (advisor)
A new methodology of polymer pipe lifetime estimation taking into account residual stresses is described in this thesis. Engineering equations derived based on numerical simulations of a hydrostatic pressure test are proposed. Residual lifetime calculations were performed for different loading conditions using experimental data of a creep crack propagation in studied material and stress distribution in the pipe wall. The effects which significantly influence lifetime estimation were quantified with special focus on residual stresses.
|
|
|
Modelling of vibration of dynamic systems with n-degrees of freedom
Luky, Robin ; Hadaš, Zdeněk (referee) ; Dušek, Daniel (advisor)
This Bachelor’s thesis deals with vibration of dynamic systems with luminous parameters with n-degrees of freedom. It features decision procedures of free-running undamped systems, exciting undamped systems, exciting damped systems and their natural shapes, natural frequency and gain-frequency characteristic. At the end of this Bachelor thesis there is an analysis of dynamic damper. The analysis is conducted in agreement with the theoretical procedures listed above.
|
|
|
The influence of residual stresses on the polymer pipe lifetime
Luky, R. ; Zouhar, Michal ; Hutař, Pavel
The aim of this article is study the influence of residual stresses on the pipe lifetime. The two dimensional numerical model of the pipe with inner crack was created and the creep crack growth in the pipe with and without residual stress is modelled. The results of K-kalibration curves are presented. After that the Paris law is used for solving the lifetime. The results of time to failure in dependency on the hoop stress for pipe with and without residual stress were compared. The existence of residual stresses decrease the lifetime of the pipe. Combination of the creep crack growth tests and numerical simulations can be a very powerful tool for lifetime estimation of plastic pipes under different loading conditions.
|
guest ::
RSS feed.