DFG SFB/Transregio 39 PT-PIESA
SFB/TR 39 - PT-PIESA

Simulation of Curing and Shrinking Processes of Joining Materials in malleable Piezo-Metal-Compounds

J. Ihlemann
  1. Aims
  2. Results
  3. Methods
  4. Publications
  5. Contact

 

Aims

Process chain Forming

  • Series production process:
    automatable processes for adhesive application, piezo positioning and heat input
  • short cycle times
 b06

 

Conceptual approach of the process chain Forming

 

Subproject C07

  • Simulation of gelation and curing
  • Integrated implementation of the simulation concept in cooperation with subproject B01
  • Fully coupled thermo-mechanical-chemical simulation
  • Calculation of residual stresses, secondary deformations and piezo loading
  • Prediction of process windows by systematic parameter variations
  • Investigation of optimal production processes

 

Results


Experimental characterization and phenomenological material modelling

Curing reaction and degree of cure: Differential Scanning Calorimetry (DSC)

Cold curing 2 component epoxy adhesive:

  • Initiation of curing at room temperature possible
  • Curing reaction not stoppable at room temperature
  • Partial gelation only conditionally possible

Heat curing 1 component polyurethane adhesive:

  • Curing reaction initiated only at temperatures >80°C
  • Reaction can be interrupted by cooling down
  • Partial gelation possible

 

Mechanical properties

Cold curing 2 component epoxy adhesive:

  • Viscoelastic behaviour
  • Moderate strains
  • Glass transition temperature within temperature range of application

Heat curing 1 component polyurethane adhesive:

  • Elastomeric behaviour
  • Large strains
  • Relaxation (viscoelasticity)

 

Thermomechanically coupled material model

Cold curing 2 component epoxy adhesive:

  • Viskoelastic model based on generalized Maxwell model
  • Equilibrium stress formulated by rate-type elasticity with process-dependent stiffness

Heat curing 1 component polyurethane adhesive:

  • Application of the MORPH-model to simulate the basic elastomeric behaviour

 

Finite element modelling
  • Thermal simulation of partial gelation
  

 

  • Geometry of formed parts as starting point for curing simulations

 

  • Thermomechanical simulation: Analysis of piezo loadings and secondary deformations

 

 

 

 

 

 

 

 

 

 

 

Methods

Material characterization
  • Reaction enthalpy and heat capacity: DSC (dynamical & isothermal)
  • Mechanical properties during the curing process: torsional rheometer
  • Mechanical properties in the fully cured state: DMA, rheometer, uniaxial tension tests in tempered environment
  • Thermal conductivity: measurement of thermal diffusivity and recalculation
  • Thermal expansion an curing shrinkage: measurement device based on Archimedes buoyancy principle

  

 

Material modelling and parameter identification

Material modelling

  • Degree of cure q
  • Volume changes
  • Heat dissipation due to curing reaction
  • Different approaches to simulate the mechanical behaviour
    - Extension by curing dependent properties
  • Evaluation of the laws of thermodynamics and derivation of the transient heat equation

 

Parameter identification

  • Implementation of the material model into a software for the simulation of homogeneous deformation processes
  • Integration into a numerical optimization tool for the automatic identification of material parameters
  • Parameter identification based on experimental data

 

FEM simulation tools
  • Fully thermomechanically coupled simulation
  • Implementation of material modes by the user subroutine USRMAT
  • Staggered solution scheme provided by ANSYS™
  • Thermal simulation of partial gelation
  • Thermomechanically coupled simulation of piezo loadings and secondary deformations during the curing process

 

  •  

Publications

Reviewed Publications

 

[Shu13a] 

Shutov A V, Landgraf R, Ihlemann J (2013)
An explicit solution for implicit time stepping in multiplicative finite strain viscoelasticity. Comput Methods Appl Mech Eng 265:213-225

[Lan14]

Landgraf R, Scherzer R, Rudolph M, Ihlemann J (2014)
Modelling and simulation of adhesive curing processes in bonded piezo metal composites. Comput Mech 54(2):547-565

[Kie16]

Kießling R, Landgraf R, Scherzer R, Ihlemann J (2016)
Introducing the concept of directly connected rheological elements by reviewing rheological models at large strains. Int J Solid Struct 97-98:650-66

[Rud16]

Rudolph M, Naumann C, Stockmann M (2016)
Degree of Cure Definition for an Epoxy Resin Based on Thermal Diffusivity Measurements. Materials Today: Proceedings 3(4):1144-1149

[Lan16a]

Landgraf R (2016)
Modellierung und Simulation der Aushärtung polymerer Werkstoffe. Dissertation, TU Chemnitz, 2015. Erschienen im Verlag Dr. Hut (2016)

[Lan17]

Landgraf R, Ihlemann J (2017)
Application and extension of the MORPH model to represent curing phenomena in a PU based adhesive. In: Constitutive Models for Rubber X, edited by A. Lion, M. Johlitz. London: Taylosr & Francis Group, S. 137-143

Other Publications

 

[Neu11] 

Neugebauer R, Ihlemann J, Lachmann L, Drossel W-G, Hensel S, Nestler M, Landgraf R, Rudolph M (2011)
Piezo-metal-composites in structural parts: Technological design, process simulation and material modelling. In: Proc CRC/Transregio 39, Chemnitz, Germany, pp 51-56

[Lan11a] 

Landgraf R, Ihlemann J (2011)
Zur Modellierung von Aushärtevorgängen in Polymeren unter Verwendung von Stoffgesetzen der Viskoelastizität und Viskoplastizität. PAMM 11(1): 399-400

[Lan11b] 

Landgraf R, Ihlemann J, Kolmeder S, Lion A (2011)
Constitutive Modelling, Finite Element-Implementation and Simulation of thermo-mechanical Processes in curing Materials. In: Proc 17th Int Symp Plast Curr Appl. NEAT Press, USA, pp 67-69

[Lan12]

Landgraf R, Ihlemann J (2012)
On the direct connection of rheological elements in nonlinear continuum mechanics. PAMM 12(1): 307-308

[Neu13]

Neugebauer R, Ihlemann J, Lachmann L, Drossel W-G, Hensel S, Nestler M, Rudolph M (2013)
Experiments an FE-Simulation of the forming an curing process of bonded Piezo-Metal-Structures. In: Proc CRC/Transregio 39. Nuremberg, Germany, pp 103-108

[Shu13b]

Shutov AV, Landgraf R, Ihlemann J (2013)
An explicit update formula for implicit time integration within finite strain viscoelasticity. PAMM 13(1): 147-148

[Rud14]

Rudolph R, Landgraf R, Ihlemann J (2013)
Experiments, modelling and simulation of adhesive curing processes in bonded three dimensional curved piezo metal composite structures. PAMM 14(1): 235-236

[Dro15]

Drossel W-G, Müller R, Ihlemann J, Rudolph M, Hensel S, Nestler M (2015)
Local pre-curing of an adhesive for the fabrication of shaped piezo-metal-compounds; 5 Wissenschaftliches Symposium PT-PIESA, September 2015, S. 41-46

[Lan15]

Landgraf R, Shutov A V, Ihlemann J (2015)
Efficient time integration in multiplicative inelasticity. PAMM 15(1): 325-326

[Rud15]

Rudolph R, Landgraf R, Ihlemann J (2015)
FE-simulation of spatially graded gelation during adhesive´s curing. PAMM 15(1): 351-352

[Lan16b]

Landgraf R, Ihlemann J (2016)
A general modelling framework and specific mechanical approaches to simulate curing phenomena in polymers. (PAMM, zur Publikation angenommen)

[Lan17]

Landgraf R, Ihlemann J (2017)
Phenomenological modelling of curing phenomena in a PU based adhesive. PAMM 17(1): 427-428

 

Contact

Managing Director:
Prof. Dr.-Ing. habil. Jörn Ihlemann
Chemnitz University of Technology
Fakultät für Maschinenbau
Professur Festkörpermechanik
09107 Chemnitz
Telephon: +49 371 531-36946
E-Mail:

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