Advanced search options

Sorted by: relevance · author · university · date | New search

You searched for `+publisher:"Delft University of Technology" +contributor:("Van der Seijs, M.V.")`

.
Showing records 1 – 3 of
3 total matches.

▼ Search Limiters

Delft University of Technology

1. Van den Bosch, D.D. Impulse Based Substructuring Unravelled; Simulation and Coupling of Structural Dynamics in the Time Domain:.

Degree: 2014, Delft University of Technology

URL: http://resolver.tudelft.nl/uuid:238edac3-0d8a-490f-be0f-c38a5a54dfd6

One way of deriving the dynamics of a structure, is by combining the dynamics of its substructures. This concept is named ’Dynamic Substructuring’ and it allows us to cope with the increasing complexity of models by dividing them into substructures and deriving their structural dynamics independently. This allows an improvement in computational efficiency. Substructuring in the frequency domain is well established nowadays, but it is not per definition best suited for simulations containing impact-like load cases. Impulse Based Substructuring (IBS) has recently been proposed allowing analysis of the high-frequency dynamics induced by these load cases more efficiently than the so-called Frequency Based Substructuring (FBS). Unfortunately IBS is not yet as mature as its frequency based counterpart. Performing a stable substructuring operation without non-physical side-effects using experimentally obtained models is at least as extensive as when done in the frequency domain. This research is performed in order to make IBS a worthy alternative to FBS. The focus of this research is twofold.
First, methods on how to obtain a structure’s dynamics using its Impulse Response Functions (IRFs) are discussed. It is derived how structural dynamics can be obtained by the convolution product between the IRF and force loading history. It is discussed how this convolution product can be discretised and it is shown that an algorithm exists which assumes piecewise linear behaviour for both the IRF and the force loading history. This results in only a third order error in the obtained response compared to the response obtained by the original convolution.
Obtaining these IRFs is a challenge on its own. IRFs can be obtained either numerically, analytically or experimentally. It is shown how the IRFs of a multiple Degree of Freedom system is derived using Modal Superposition and how this relates to obtaining the system of IRFs numerically using two Newmark time integration methods. The errors made when obtaining IRFs experimentally are discussed and it is shown what effect they have on the simulated dynamics of the structure for varying load cases.
Since solving the convolution product for lengthy load cases becomes computational extensive, techniques to enhance computational performance are discussed. Among those a matrix recurrence procedure for modal contributions is proposed.
Secondly, the research focusses on the coupling procedure itself. It is explained how the convolution product is expanded to satisfy equilibrium and compatibility between the coupled substructures. It is shown that the main challenge is to accurately determine the forces acting on the interfaces between the substructures such that compatibility is maintained. Three coupling methods are discussed. The first method amounts an analytical procedure using the Laplace domain to obtain the interface forces. Secondly, the classical discrete coupling method is discussed, which satisfies compatibility explicitly to obtain the interface force every time step. Finally an…
*Advisors/Committee Members: Van der Seijs, M.V..*

Subjects/Keywords: Impulse Based; Substructuring; Structural Dynamics

Record Details Similar Records

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^{th} Edition):

Van den Bosch, D. D. (2014). Impulse Based Substructuring Unravelled; Simulation and Coupling of Structural Dynamics in the Time Domain:. (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:238edac3-0d8a-490f-be0f-c38a5a54dfd6

Chicago Manual of Style (16^{th} Edition):

Van den Bosch, D D. “Impulse Based Substructuring Unravelled; Simulation and Coupling of Structural Dynamics in the Time Domain:.” 2014. Masters Thesis, Delft University of Technology. Accessed December 15, 2019. http://resolver.tudelft.nl/uuid:238edac3-0d8a-490f-be0f-c38a5a54dfd6.

MLA Handbook (7^{th} Edition):

Van den Bosch, D D. “Impulse Based Substructuring Unravelled; Simulation and Coupling of Structural Dynamics in the Time Domain:.” 2014. Web. 15 Dec 2019.

Vancouver:

Van den Bosch DD. Impulse Based Substructuring Unravelled; Simulation and Coupling of Structural Dynamics in the Time Domain:. [Internet] [Masters thesis]. Delft University of Technology; 2014. [cited 2019 Dec 15]. Available from: http://resolver.tudelft.nl/uuid:238edac3-0d8a-490f-be0f-c38a5a54dfd6.

Council of Science Editors:

Van den Bosch DD. Impulse Based Substructuring Unravelled; Simulation and Coupling of Structural Dynamics in the Time Domain:. [Masters Thesis]. Delft University of Technology; 2014. Available from: http://resolver.tudelft.nl/uuid:238edac3-0d8a-490f-be0f-c38a5a54dfd6

Delft University of Technology

2. Pasma, E.A. Towards a Robust Component Transfer Path Analysis Method: Application and Validation in Automotive Research:.

Degree: 2014, Delft University of Technology

URL: http://resolver.tudelft.nl/uuid:50cd45f4-e7ec-40c4-bc0e-d544e95a0e67

A robust Transfer Path Analysis (TPA) procedure is presented to predict the transmitted vibrations of a steering gear in BMW vehicles in a multi-kHz range. The internal excitation forces are characterised as a set of equivalent forces on the interface of the active component. These equivalent forces are determined from force and acceleration measurements at the interface of the active component and a test bench. The response of the total system is calculated with the dynamic properties at the component interface onwards to a point of interest in the vehicle. Two equivalent force determination schemes are applied on two test benches with different dynamic properties. The first method relies on direct interface force measurements, whereas the second procedure is based on a matrix inverse procedure on the assembly of the steering gear and the test bench. It is shown that these equivalent forces are indeed a property of the active component only.
All methods use the virtual point transformation to build a nodal description on interfaces of the structures. This is a crucial step in Dynamic Substructuring (DS) for the connectivity between the substructures. The projection of measured Frequency Response Functions (FRFs) on local rigid interface displacement modes in a user-specified virtual point, which allow to determine rotational degrees of freedom, that are in practice unmeasurable, yet crucial for the connectivity. Pre-analysis on the transformation to interface degrees of freedom and a sufficient over-determination, enhance noise suppression and mode observability. This method is validated by means of a benchmark of three identical vehicles of which the virtual point dynamics are determined on the interface of the steering gear and the vehicle.
For a robust prediction and to get grip on the uncertainties in the analyses, all steps are evaluated separately and qualified with performance indicators.
*Advisors/Committee Members: Van Keulen, A., Van der Seijs, M.V..*

Subjects/Keywords: Robust Component; Path Analysis Method; Automotive Research

Record Details Similar Records

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^{th} Edition):

Pasma, E. A. (2014). Towards a Robust Component Transfer Path Analysis Method: Application and Validation in Automotive Research:. (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:50cd45f4-e7ec-40c4-bc0e-d544e95a0e67

Chicago Manual of Style (16^{th} Edition):

Pasma, E A. “Towards a Robust Component Transfer Path Analysis Method: Application and Validation in Automotive Research:.” 2014. Masters Thesis, Delft University of Technology. Accessed December 15, 2019. http://resolver.tudelft.nl/uuid:50cd45f4-e7ec-40c4-bc0e-d544e95a0e67.

MLA Handbook (7^{th} Edition):

Pasma, E A. “Towards a Robust Component Transfer Path Analysis Method: Application and Validation in Automotive Research:.” 2014. Web. 15 Dec 2019.

Vancouver:

Pasma EA. Towards a Robust Component Transfer Path Analysis Method: Application and Validation in Automotive Research:. [Internet] [Masters thesis]. Delft University of Technology; 2014. [cited 2019 Dec 15]. Available from: http://resolver.tudelft.nl/uuid:50cd45f4-e7ec-40c4-bc0e-d544e95a0e67.

Council of Science Editors:

Pasma EA. Towards a Robust Component Transfer Path Analysis Method: Application and Validation in Automotive Research:. [Masters Thesis]. Delft University of Technology; 2014. Available from: http://resolver.tudelft.nl/uuid:50cd45f4-e7ec-40c4-bc0e-d544e95a0e67

3. Van der Horst, T. Experimental dynamic substructuring using direct time-domain deconvolved impulse response functions:.

Degree: 2014, Delft University of Technology

URL: http://resolver.tudelft.nl/uuid:53fe2f3a-7f75-4ed0-a9b0-0bd8c356ee19

The dynamics of systems can be analysed by combining the dynamics of its components. This method is generally know as dynamic substructuring. It allows for efficient computation of the dynamics of structures that would otherwise be to complex to determine. Most dynamic substructuring approaches use the frequency domain for the re-assembling of the subcomponents. Recently, a different implementation of the dynamic substructuring method has been introduced: impulse based substructuring (IBS). It uses impulse response function in the time-domain for representing the dynamics of the subcomponents, obtained by numerical models or experimental testing. Compared to the frequency domain methods, the impulse based substructuring scheme proves to be advantageous when analysing the high-frequency characteristics of a system. The high-frequency dynamics are excited when the system is subjected to blasts, shocks or impulsive loading. Due to the sensitivity of the impulse based substructure scheme, experimentally obtained impulse response functions can not be used for describing the dynamics of a subsystem.
The focus of this thesis is developing a direct time-domain technique for determining the experimental impulse response. This is realised by introducing the inverse finite impulse response force filter, which operates independent of the output system response. This time-domain approach will avoid frequency domain induced errors, i.e. windowing, anti-aliasing and Fourier transforms, in the effort of determining a highly accurate impulse response functions. The quality of the time-domain acquired impulse response, as well as the measurement induced errors are tested on the impulse based substructuring scheme. The procedures are illustrated by application to an one-dimensional bar.
The inverse force filter is successful in finding the experimental (averaged) impulse response. The accuracy of the filter depends on the length of the filter and the conditioning of the force auto correlation matrix. The eigenvalue decomposition of this matrix led to the formulation of a selection criteria between replicate measurements and a filtering operation. The inverse filter can also be defined by using a Fourier transform and its inverse. If both methods are compared, it is shown that the time-domain approach is less accurate and time efficient.
The direct time-domain approach did not change the impulse response in such an extend that coupling by the impulse based substructuring scheme was possible. Since coupling between numerically simulated data is possible, measurement errors are introduced on the impulse response functions to test their sensitivity to the IBS scheme. It is observed that a small error on the exponential decay, of the perfect impulse response, directly resulted in uncoupled full system responses. This led to the identification of the modal parameters of the measurement to get rid of these amplitude errors, by means of the least squares complex exponential method. The perfect synthesised impulse response are successful in…
*Advisors/Committee Members: Van der Valk, P.L.C., Van der Seijs, M.V..*

Subjects/Keywords: Dynamic substructuring; Experimental; Impulse response; Deconvolution; Time-domain; Inverse finite impulse response filter

Record Details Similar Records

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^{th} Edition):

Van der Horst, T. (2014). Experimental dynamic substructuring using direct time-domain deconvolved impulse response functions:. (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:53fe2f3a-7f75-4ed0-a9b0-0bd8c356ee19

Chicago Manual of Style (16^{th} Edition):

Van der Horst, T. “Experimental dynamic substructuring using direct time-domain deconvolved impulse response functions:.” 2014. Masters Thesis, Delft University of Technology. Accessed December 15, 2019. http://resolver.tudelft.nl/uuid:53fe2f3a-7f75-4ed0-a9b0-0bd8c356ee19.

MLA Handbook (7^{th} Edition):

Van der Horst, T. “Experimental dynamic substructuring using direct time-domain deconvolved impulse response functions:.” 2014. Web. 15 Dec 2019.

Vancouver:

Van der Horst T. Experimental dynamic substructuring using direct time-domain deconvolved impulse response functions:. [Internet] [Masters thesis]. Delft University of Technology; 2014. [cited 2019 Dec 15]. Available from: http://resolver.tudelft.nl/uuid:53fe2f3a-7f75-4ed0-a9b0-0bd8c356ee19.

Council of Science Editors:

Van der Horst T. Experimental dynamic substructuring using direct time-domain deconvolved impulse response functions:. [Masters Thesis]. Delft University of Technology; 2014. Available from: http://resolver.tudelft.nl/uuid:53fe2f3a-7f75-4ed0-a9b0-0bd8c356ee19