Modelling and simulation of adhesive curing processes in bonded piezo metal composites

Ihlemann

2019

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Within numerical simulations of mechanical systems, not only the geometry, boundary conditions, the material behavior and the included material parameters have to defined. Beyond that, initial conditions have to be set properly in order to define the initial state of the material. In this contribution, two different examples of proper definition of initial values are regarded and their impact on the simulation results is discussed. The first example is devoted to models including elasto‐ or viscoplastic material behavior. Here initial values of plastic internal variables enable the consideration of the loading history. Thereby, a change of the reference configuration has to be taken into account. The second example highlights the impact of initial values for the temperature and similar physical properties that control the initial volume of a material with volume‐changing capabilities (like heat expansion, swelling or polymerization shrinkage).

“…the progress of the curing process, see for example [3]). Moreover, θ > 0 is the temperature and q ∈ [0, 1] is the degree of cure (i.e.…”

Section: Preservation Of a Constant Initial Volumementioning

confidence: 99%

Section: Preservation Of a Constant Initial Volumementioning

confidence: 99%

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On the change of the reference configuration and its application within FEM simulations

Ihlemann

2019

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“…To this end, the viscoelastic material model including the curing process was implemented by the help of user-subroutines. Here, a newly developed algorithm assures a constant initial mesh volume at arbitrary distributed values for the temperature and the degree of cure [5]. During the curing simulations, the temperature, the degree of cure as well as stresses and deformations are monitored and evaluated.…”

Section: Modelling and Computation Frameworkmentioning

confidence: 99%

Modelling and computation of acrylic bone cement injection and curing within the framework of vertebroplasty

Ihlemann

Kolmeder³

et al. 2014

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This contribution deals with the simulation based investigation of processes related to the surgical treatment of vertebroplasty. In this regard, a simulation framework has been developed, which includes the generation of microstructural computer models of cancellous bone structures, the simulation of bone cement injection by computational fluid dynamics (CFD) methods and finite element (FE) simulations of bone cement curing processes. The modelling and computation strategy is illustrated and different material modelling approaches for the representation of acrylic bone cements as a non-linear fluid and a non-linear viscoelastic solid with curing dependent properties are outlined.

“…Based on the evaluation of the laws of thermodynamics, a continuum mechanical material model for the adhesive is deduced. It is based on the multiplicative decomposition of the deformation gradient into a thermochemical and a mechanical part in first place and into a volume changing and volume preserving part of the latter [2]. Thermochemical processes are assumed to be isotropic and follow an exponential model identified by the measurements based on DSC and Archimedes principle [2,4].…”

Section: Experimental Characterisationmentioning

confidence: 99%

Experiments, modelling and simulation of adhesive curing processes in bonded three dimensional curved piezo metal composite structures

Rudolph

Scherzer

et al. 2014

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This contribution deals with the modelling and simulation of curing phenomena in adhesively bonded piezo metal composites which consists of a piezoelectric module enclosed by an adhesive layer which in turn is surrounded by two metal sheets. A short survey on the neccessary experimental investigations to characterise the adhesive's material behaviour is given and important aspects on the corresponding phenomenological modelling approach are presented. Both steps take into account the curing reaction, changes of volume, like chemical shrinkage, and inelastic mechanical behaviour which is temperature and curing dependent. Finally, the simulation strategy for the modelling within a finite element environment is depicted. By this, residual stresses, secondary deformations and loads on the piezo modules can be predicted, which is exemplified by a comparative study verifying a novel manufacturing strategy.