Sökning: "rainflow"

Visar resultat 1 - 5 av 7 avhandlingar innehållade ordet rainflow.

1. 1. Rainflow Analysis of Switching Markov Loads

   Författare :Pär Johannesson; Matematisk statistik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; actuarial mathematics; programming; operations research; Statistics; rainflow matrix; fatigue; vehicle load; hidden Markov model; random load; Markov model; Switching process; Statistik; operationsanalys; programmering; aktuariematematik;

   Sammanfattning : Rainflow cycles are often used in fatigue analysis of materials for describing the variability of applied loads. Therefore, an important characteristic of a random load process is the intensity of rainflow cycles, also called the expected rainflow matrix (RFM), which can be used for evaluation of the fatigue life. LÄS MER

3. 2. Fatigue Assessment and Extreme Response Prediction of Ship Structures

   Författare :Wengang Mao; Göteborgs universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Fatigue assessment; extreme response; rainflow; narrow-band approximation; Laplace Moving Average model; transformed Gaussian; zero up-crossing response frequency; significant wave height; safety index; upcrossing spectrum; long term cumulative distribution function; ship routing.; transformed Gaussian;

   Sammanfattning : In this thesis, a simplified narrow-band approximation model is proposed to estimate fatigue damage of ship structures, and an efficient method for extreme response predictions is also developed using upcrossing spectrums of ship responses. The proposed fatigue model includes two main parameters, significant stress range hs and zero upcrossing frequency fz. LÄS MER

4. 3. Utmattningsanalys av järnvägsbroar : En fallstudie av stålbroarna mellan Stockholm Central och Söder Mälarstrand, baserat på teoretiska analyser och töjningsmätningar

   Författare :Andreas Andersson; Håkan Sundquist; Kjell Eriksson; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Fatigue; Palmgren-Miners cumulative damage theory; Rainflow-analysis; railway bridges; finite element methods; Utmattning; Palmgren-Miners delskadehypotes; Rainflow-analys; järnvägsbroar; finita element metoder; Civil engineering and architecture; Samhällsbyggnadsteknik och arkitektur;

   Sammanfattning : Föreliggande avhandling omfattar en fallstudie av utmattningsrisken för järnvägsbroarna mellan Stockholm Central och Söder Mälarstrand. Ett stort antal utmattningssprickor i broarna över Söderström och Söder Mälarstrand har sedan länge varit kända. LÄS MER

5. 4. A statistical approach to multi-input equivalent fatigue loads for the durability of automotive structures

   Författare :Gwenaelle Genet; Göteborgs universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Equivalent fatigue; uniaxial and multiaxial high cycle fatigue; multi-input variable amplitude loads; rainflow counting; Morel s model; Basquin s model; Gaussian process; Markov chain; Markov chain;

   Sammanfattning : In the automotive industry, due to temporal and financial constraints, we need to strongly reduce the duration of the design phase, but still ensure reliability and robustness. Structures in service are often exposed to complex variable amplitude loads. LÄS MER

7. 5. Random Fatigue Analysis of Container Ship Structures

   Författare :Wengang Mao; Göteborgs universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; RAOs; rainflow counting; narrow band approximation; zero up-crossing response frequency; significant wave height; ship structure response; S-N curve; spatio-temporal model; safety index.; zero up-crossing response frequency;

   Sammanfattning : .... LÄS MER