Search for dissertations about: "complex modal synthesis"

Showing result 1 - 5 of 6 swedish dissertations containing the words complex modal synthesis.

  2. 1. Modal analysis and synthesis in transient vibration and structural optimization problems

    Author : Thomas Abrahamsson; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Complex modal analysis; transient analysis; nonproportional damping; adjoint eigenproblems; follower forces; structural optimization; nonconservative systems; sensitivity analysis; linear continous structural systems; moving loads;

    Abstract : .... READ MORE

  4. 2. Development of Accurate Reduced Order Models in a Simulation Tool for Turbomachinery Aeromechanical Phenomena

    Author : Mauricio Gutierrez Salas; Björn Laumert; Paul Petrie-Repar; Damian Vogt; Carlos Martel; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; flutter; forced response; high cycle fatigue; reduced order models; ROM; craig-bampton; mistuning; tuned; mistuned; cyclic; noncyclic; craig-chang; free-interface. fixed-interface; subset nominal mode; SNM; CBMS; CCMS; CCC; CBC; FEM; CMS; modal; eigen; modeshapes; aeroelasticity; aeromechanical; tool; turbomachinery; turbine; compressor; AROMA; Energy Technology; Energiteknik;

    Abstract : Modern gas turbines are still vulnerable to vibrations when operated at certain speeds. This unstable environment can lead to high cycle fatigue (HCF) and damage several of the components inside the turbine. READ MORE

  5. 3. Fluid-conveying beams in transverse vibration

    Author : Jan Henrik Sällström; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; plug flow; ambient medium; support accelerations; rigid bodies; complex modal synthesis; exact and polynominal finite elements; taut strings; Rayleigh-Timoshenko theory; transverse linear beam vibration; prescribed loads; sensitivity analysis; stability optimization; divergence and flutter instability; Euler-Bernoulli theory; axially moving materials; stationary and transient vibration;

    Abstract : .... READ MORE

  6. 4. Identification and synthesis of components for uncertainty propagation

    Author : Mladen Gibanica; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; substructuring; uncertainty propagation; uncertainty quantification; surrogate modelling; Monte Carlo method; interface reduction; state-space models; experimental methods; system identification;

    Abstract : For automotive structures, built-up of hundreds of components with property spread, knowing the effects of component variability and its propagation through the system assembly is important in order to mitigate noise and vibration problems. To increase the understanding of how the spread propagates into variability in built-up structures, both experimental and computational aspects are considered in this thesis. READ MORE

  7. 5. Efficient Finite Element Approach for Structural-Acoustic Applications including 3D modelling of Sound Absorbing Porous Materials

    Author : Romain Rumpler; Peter Göransson; Jean-François Deü; Henry Rice; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Noise reduction; Poroelastic materials; Reduced model; Component mode synthesis; Padé approximants; Structural-acoustics; Finite element method; Fluid-structure interaction.; Matériaux poroélastiques; Modèles réduits; Sous-structuration dynamique; Approximants de Padé; Vibroacoustique interne; Eléments finis; Interaction fluid-structure.; Järnvägsgruppen - Ljud och vibrationer; Järnvägsgruppen - Ljud och vibrationer;

    Abstract : In the context of interior noise reduction, the present work aims at proposing Finite Element (FE) solution strategies for interior structural-acoustic applications including 3D modelling of homogeneous and isotropic poroelastic materials, under timeharmonic excitations, and in the low frequency range. A model based on the Biot-Allard theory is used for the poroelastic materials, which is known to be very costly in terms of computational resources. READ MORE