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Simulation of Bond-Line Read-Through effects

Davidsson, Anders LU (2015) In TFHF-5204 FHL820 20151
Solid Mechanics
Abstract
The occurrence of deformations on the surface of adhesively-bonded automotive body panels in proximity to the application of the polymer adhesive is called bond-line read-through (BLRT) and occurs due to process-induced differential thermal strains between the adhesive layer and metal substrate. This type of deformation is a major problem in the automotive industry and one Volvo Car Corporation, who are well known for their high quality standards, are keen to eliminate. By constructing a computational model using the finite element method this thesis work addresses the problem of simulating a viscoelastic epoxy material’s behavior when applied to a steel surface. The computational model was created mainly using the commercial software Ansa... (More)
The occurrence of deformations on the surface of adhesively-bonded automotive body panels in proximity to the application of the polymer adhesive is called bond-line read-through (BLRT) and occurs due to process-induced differential thermal strains between the adhesive layer and metal substrate. This type of deformation is a major problem in the automotive industry and one Volvo Car Corporation, who are well known for their high quality standards, are keen to eliminate. By constructing a computational model using the finite element method this thesis work addresses the problem of simulating a viscoelastic epoxy material’s behavior when applied to a steel surface. The computational model was created mainly using the commercial software Ansa and Abaqus where the viscoelastic properties of the material were implemented using data obtained through Dynamic Mechanical Thermal Analysis (DMTA). The principle of time-temperature superposition was used in order to first convert the raw data into so-called master curves which describe the time and temperature dependent behavior of the material. In order to evaluate the epoxy’s aptitude for inducing BLRT effects on a steel surface the curvature of bimaterial beams (steel beams coated with epoxy adhesive) when exposed to a temperature difference were examined. Measurements of bimaterial beam specimens compared to simulated values were determined not to correspond in a satisfactory manner. Potential problems with the material model, such as the lack of including the effects of moisture absorption, etc., are discussed and further efforts needed in the future are also presented. (Less)
Popular Abstract (Swedish)
Inom bilindustrin utvecklas kontinuerligt nya sätt att förbättra kvalitén, säkerheten och komforten i de bilarna man producerar, speciellt inom den avancerade kategori bilar som Volvo Car Corporation (VCC) framställer. Detta har lett till att man i allt större grad använder sig av lim, eller fästmedel, av så kallade polymerer som visat sig vara mycket användbara för att dämpa ljud och vibrationer. Man arbetar dessutom mycket hårt för att göra de bilar man producerar mer miljövänliga. Ett sätt att göra detta är att använda tunnare plåtar i karossen, vilket minskar bilarnas vikt och därmed också minskar den mängd drivmedel de förbrukar. Dessa tunna plåtar fästs vid karossen med bland annat dessa polymera fästmedel. Användandet av dessa... (More)
Inom bilindustrin utvecklas kontinuerligt nya sätt att förbättra kvalitén, säkerheten och komforten i de bilarna man producerar, speciellt inom den avancerade kategori bilar som Volvo Car Corporation (VCC) framställer. Detta har lett till att man i allt större grad använder sig av lim, eller fästmedel, av så kallade polymerer som visat sig vara mycket användbara för att dämpa ljud och vibrationer. Man arbetar dessutom mycket hårt för att göra de bilar man producerar mer miljövänliga. Ett sätt att göra detta är att använda tunnare plåtar i karossen, vilket minskar bilarnas vikt och därmed också minskar den mängd drivmedel de förbrukar. Dessa tunna plåtar fästs vid karossen med bland annat dessa polymera fästmedel. Användandet av dessa fästmedel kan leda till problem såsom små deformationer på plåtarna vid platsen där limmet applicerats. Dessa deformationer kallas för ”Bond-Line Read-Through” (ofta förkortat till BLRT) deformationer och uppkommer på grund av skillnader i termiska materialegenskaper mellan stålet i plåtarna och limmet. Eftersom man vill undvika att använda fästmedel som kan ge upphov till dessa BLRT-deformationer efterfrågade VCC en datormodell som kunde simulera hur dessa fästmedel beter sig då de appliceras på en plåt. Denna datormodell skulle funka som ett verktyg för att kunna utvärdera olika fästmedel. (Less)
Please use this url to cite or link to this publication:
author
Davidsson, Anders LU
supervisor
organization
course
FHL820 20151
year
type
H3 - Professional qualifications (4 Years - )
subject
keywords
Finite element modeling, Bond-Line Read-Out, Viscoelastic adhesive modeling, Bond-Line Read-Through
publication/series
TFHF-5204
report number
LUTFD2/TFHF-15/5204-SE(1-63)
language
English
id
7867863
date added to LUP
2016-09-14 10:37:19
date last changed
2016-09-14 10:37:19
@misc{7867863,
  abstract     = {The occurrence of deformations on the surface of adhesively-bonded automotive body panels in proximity to the application of the polymer adhesive is called bond-line read-through (BLRT) and occurs due to process-induced differential thermal strains between the adhesive layer and metal substrate. This type of deformation is a major problem in the automotive industry and one Volvo Car Corporation, who are well known for their high quality standards, are keen to eliminate. By constructing a computational model using the finite element method this thesis work addresses the problem of simulating a viscoelastic epoxy material’s behavior when applied to a steel surface. The computational model was created mainly using the commercial software Ansa and Abaqus where the viscoelastic properties of the material were implemented using data obtained through Dynamic Mechanical Thermal Analysis (DMTA). The principle of time-temperature superposition was used in order to first convert the raw data into so-called master curves which describe the time and temperature dependent behavior of the material. In order to evaluate the epoxy’s aptitude for inducing BLRT effects on a steel surface the curvature of bimaterial beams (steel beams coated with epoxy adhesive) when exposed to a temperature difference were examined. Measurements of bimaterial beam specimens compared to simulated values were determined not to correspond in a satisfactory manner. Potential problems with the material model, such as the lack of including the effects of moisture absorption, etc., are discussed and further efforts needed in the future are also presented.},
  author       = {Davidsson, Anders},
  keyword      = {Finite element modeling,Bond-Line Read-Out,Viscoelastic adhesive modeling,Bond-Line Read-Through},
  language     = {eng},
  note         = {Student Paper},
  series       = {TFHF-5204},
  title        = {Simulation of Bond-Line Read-Through effects},
  year         = {2015},
}