Prediction of weld distortions in body-in-white for geometrical qualiTy assurancE Oscar Andersson

19 Pages·2017·1.98 MB·English

by  Andersson, Oscar

Prediction of weld distortions for geometrical
qualiTy assurancE
Oscar Andersson, Volvo cars
2017-09-06 PREDICTION OF WELD DISTORTIONS FOR GEOMETRICAL QUALITY ASSURANCE; OSCAR ANDERSSON, 81210; STATUS: PUBLIC 1
background
• Geometrical quality is essential for
structrual integrity and visual
apperance of vechicles
• Welding and assembly will affect
nominal geometries (distortions) of
products due to heat input and natural
variations
• Efficient prediction of geometrical
distortipons may reduce distortions
and optimize manufacturing
processes and reduce lead times
2017-09-06 PREDICTION OF WELD DISTORTIONS FOR GEOMETRICAL QUALITY ASSURANCE; OSCAR ANDERSSON, 81210; STATUS: PUBLIC 2
laserlight
VINNOVA FFI Funded research project to analyze distortions due to laser beam welding
2013 - 2016
2017-09-06 PREDICTION OF WELD DISTORTIONS FOR GEOMETRICAL QUALITY ASSURANCE; OSCAR ANDERSSON, 81210; STATUS: PUBLIC 3
Hypotheses and methodology
Experiments
Increased use of
Increased use of
Process planning
laser beam
UHSS strategy
welding
Simulations
Lightweight strategy in industry
2017-09-06 PREDICTION OF WELD DISTORTIONS FOR GEOMETRICAL QUALITY ASSURANCE; OSCAR ANDERSSON, 81210; STATUS: PUBLIC 4
Experimental setup
• Experiments on idelized beam
geometries – hat profiles
• Materials:
• 22MnB5, DP800, Mild steel
• Thickness = 1 mm
• Laser beam welded and
geometrical distortions were
measured
2017-09-06 PREDICTION OF WELD DISTORTIONS FOR GEOMETRICAL QUALITY ASSURANCE; OSCAR ANDERSSON, 81210; STATUS: PUBLIC 5
Experimental results
Single hat profile – longitudinal bending Double hat profile – transverse distortions
u
y
u
z
Significant influencing factors:
• Beam geometry
• Heat input
• Material grade
2017-09-06 PREDICTION OF WELD DISTORTIONS FOR GEOMETRICAL QUALITY ASSURANCE; OSCAR ANDERSSON, 81210; STATUS: PUBLIC 6
FEM Simulations of Laser Beam Welding
• Opportunity to reduce lead times and costs and
optimize process parameters.
• Increase understanding of process in terms of y
c
a
heat transfer and mechanical behaviour r
u
c
c
a

n
o Simulation method
• Increased implementation of joining in virtual it
a
l shouldbe customised
manufacturing and product development u
m
environments iS for application and
needs
• Challenges in material modeling, Material data,
computer efficiency and implementation
Simulation time
2017-09-06 PREDICTION OF WELD DISTORTIONS FOR GEOMETRICAL QUALITY ASSURANCE; OSCAR ANDERSSON, 81210; STATUS: PUBLIC 7
General simulation flow
Thermal
data:
Thermal heat Density Temperature
source Heat field
conductivity
Specificheat
3 simulation
approaches were
investigated
Mechanical
data:
Displacements Elasticdata
Thermal
Plastic data strains
Phase
transformations
2017-09-06 PREDICTION OF WELD DISTORTIONS FOR GEOMETRICAL QUALITY ASSURANCE; OSCAR ANDERSSON, 81210; STATUS: PUBLIC 8
1. transient solution
Thermal
data:
Thermal heat Density Temperature
source Heat field
conductivity
Specificheat
2-3 days
Mechanical
data:
Displacements Elasticdata
Thermal
Plastic data strains
Phase
transformations
2017-09-06 PREDICTION OF WELD DISTORTIONS FOR GEOMETRICAL QUALITY ASSURANCE; OSCAR ANDERSSON, 81210; STATUS: PUBLIC 9
2. Shrinakge method
Thermal
data:
Manually defined
Thermal heat Density Temperature
temperature field
source Heat field
conductivity
Specificheat
~20 minutes
Much faster!
Mechanical
data:
Requires
Displacements Elasticdata
Thermal
Plastic data strains calibration
Phase
transformations
2017-09-06 PREDICTION OF WELD DISTORTIONS FOR GEOMETRICAL QUALITY ASSURANCE; OSCAR ANDERSSON, 81210; STATUS: PUBLIC 10