Advanced

Dynamic Analysis of the Interaction Between Vehicle Floor Panels and Interior Carpets - Simulations and Measurements

Dias Dos Santos Ingesson, Jakob LU (2019) In TVSM-5000 VSMM01 20191
Structural Mechanics
Department of Construction Sciences
Abstract
Floor panels of vehicles are known to radiate structure-borne sound into the vehicle compartment. To reduce the structure-borne sound, numerical models are used in the development of vehicles to evaluate different design options of the vehicle body. The panels are covered with carpets composed of foam and heavy layer of rubber, which causes challenges and complications when predicting interior sound.

In the current models used to predict sound, the carpets are modelled as non-structural mass added to the panels. It is believed that the heavy layer setup of the carpets leads to a sprung-mass resonance in the frequency of interest for structure-borne sound. This affects the dynamic behaviour and sound radiation of the floor panels.... (More)
Floor panels of vehicles are known to radiate structure-borne sound into the vehicle compartment. To reduce the structure-borne sound, numerical models are used in the development of vehicles to evaluate different design options of the vehicle body. The panels are covered with carpets composed of foam and heavy layer of rubber, which causes challenges and complications when predicting interior sound.

In the current models used to predict sound, the carpets are modelled as non-structural mass added to the panels. It is believed that the heavy layer setup of the carpets leads to a sprung-mass resonance in the frequency of interest for structure-borne sound. This affects the dynamic behaviour and sound radiation of the floor panels. Further, the panels and carpets are believed to not be in full contact with each other, and the contact condition is assumed to vary among vehicles and over time. Therefore it is assumed that the current modelling strategy used to model floor panels is not able to predict the dynamic behaviour of the panels and carpets with sufficient accuracy. This leads to erroneous results and conclusions in the development of cars.

A step towards a modelling strategy capable of predicting interior noise levels with higher accuracy, is to understand the dynamic behaviour of panels and carpets. In this Master's dissertation, an example structure of a floor panel with carpet is studied experimentally and numerically. The effect of the carpet on the dynamic response in the panel, and the response in the panel compared to that in the heavy layer is investigated. It was found that a model with a simple linear-elastic solid representation of the carpet is able to represent the basic phenomena that govern the dynamic behaviour of panels and carpets. Although, further investigation is needed to achieve adequate correlation of the vibration levels and resonance frequencies. A sprung-mass resonance of the carpet was clearly observed in both measurements and numerical analyses. A significant effect of contact condition between panel and carpet was also found. (Less)
Popular Abstract (Swedish)
I designen av en ny bil används datormodeller för att förutsäga olika slags beteende. Ett exempel på ett sådant beteende är hur golvpanelerna vibrerar. Detta är av intresse eftersom golvpanelerna genererar ljud när de vibrerar, vilket uppfattas som buller. Golvpanelerna täcks därför med mattor som minskar ljudnivån i kupén. Problematiken som uppstår är att interaktionen mellan mattor och golvpaneler är komplex och svår att förutsäga med befintliga beräkningsmodeller. Detta bidrar till svårigheter i designarbetet av bilen, vilket kan resultera i högre ljudnivåer än önskat.
Please use this url to cite or link to this publication:
author
Dias Dos Santos Ingesson, Jakob LU
supervisor
organization
course
VSMM01 20191
year
type
H3 - Professional qualifications (4 Years - )
subject
publication/series
TVSM-5000
report number
TVSM-5239
ISSN
0281-6679
language
English
id
8990295
alternative location
http://www.byggmek.lth.se/english/publications/tvsm-5000-present-2014/
date added to LUP
2019-07-17 12:41:34
date last changed
2019-07-17 12:41:34
@misc{8990295,
  abstract     = {Floor panels of vehicles are known to radiate structure-borne sound into the vehicle compartment. To reduce the structure-borne sound, numerical models are used in the development of vehicles to evaluate different design options of the vehicle body. The panels are covered with carpets composed of foam and heavy layer of rubber, which causes challenges and complications when predicting interior sound.
 
In the current models used to predict sound, the carpets are modelled as non-structural mass added to the panels. It is believed that the heavy layer setup of the carpets leads to a sprung-mass resonance in the frequency of interest for structure-borne sound. This affects the dynamic behaviour and sound radiation of the floor panels. Further, the panels and carpets are believed to not be in full contact with each other, and the contact condition is assumed to vary among vehicles and over time. Therefore it is assumed that the current modelling strategy used to model floor panels is not able to predict the dynamic behaviour of the panels and carpets with sufficient accuracy. This leads to erroneous results and conclusions in the development of cars.
 
A step towards a modelling strategy capable of predicting interior noise levels with higher accuracy, is to understand the dynamic behaviour of panels and carpets. In this Master's dissertation, an example structure of a floor panel with carpet is studied experimentally and numerically. The effect of the carpet on the dynamic response in the panel, and the response in the panel compared to that in the heavy layer is investigated. It was found that a model with a simple linear-elastic solid representation of the carpet is able to represent the basic phenomena that govern the dynamic behaviour of panels and carpets. Although, further investigation is needed to achieve adequate correlation of the vibration levels and resonance frequencies. A sprung-mass resonance of the carpet was clearly observed in both measurements and numerical analyses. A significant effect of contact condition between panel and carpet was also found.},
  author       = {Dias Dos Santos Ingesson, Jakob},
  issn         = {0281-6679},
  language     = {eng},
  note         = {Student Paper},
  series       = {TVSM-5000},
  title        = {Dynamic Analysis of the Interaction Between Vehicle Floor Panels and Interior Carpets - Simulations and Measurements},
  year         = {2019},
}