Mixed methods for viscoelastodynamics and topology optimization
Journal Title: Frattura ed Integrità Strutturale - Year 2014, Vol 8, Issue 29
Abstract
A truly-mixed approach for the analysis of viscoelastic structures and continua is presented. Anadditive decomposition of the stress state into a viscoelastic part and a purely elastic one is introduced alongwith an Hellinger-Reissner variational principle wherein the stress represents the main variable of theformulation whereas the kinematic descriptor (that in the case at hand is the velocity field) acts as Lagrangemultiplier. The resulting problem is a Differential Algebraic Equation (DAE) because of the need to introducestatic Lagrange multipliers to comply with the Cauchy boundary condition on the stress. The associatedeigenvalue problem is known in the literature as constrained eigenvalue problem and poses several difficultiesfor its solution that are addressed in the paper. The second part of the paper proposes a topology optimizationapproach for the rationale design of viscoelastic structures and continua. Details concerning densityinterpolation, compliance problems and eigenvalue-based objectives are given. Worked numerical examples arepresented concerning both the dynamic analysis of viscoelastic structures and their topology optimization.
Authors and Affiliations
Giacomo Maurelli, Nadia Maini, Paolo Venini
Keywords
Related Articles
- EP ID EP99744
- DOI 10.3221/IGF-ESIS.29.31
- Views 71
- Downloads 0
Effect of defect length on rolling contact fatigue crack propagation in high strength steel
The objective of the present paper is to clarify the effect of defect length in depth direction on rolling contact fatigue (RCF) crack propagation in high strength steel. RCF test and synchrotron radiation micro&n...
Mechanical properties of copper processed by Equal Channel Angular Pressing – a review
The Equal Channel Angular Pressing is a hardening treatment with which ductile metals can be processed to refine their grain and sub-grain structure. This process enhances the mechanical strength of metals in terms...
On the crack path under mixed mode loading on PUR foams
In this paper are presented the crack initiation angles obtained in polyurethane (PUR) foams under mixed mode loading. Closed cell rigid PUR foams having three different densities 100, 145, and 300 kg/m3 were inve...
Fatigue crack propagation in short-fiber reinforced plastics
The influence of fiber orientation on the crack propagation behavior was studied with single edgenotched specimens which were cut from an injection-molded plate of short-fiber reinforced plastics of polyp...
Numerical modelling of intergranular fracture in polycrystalline materials and grain size effects
In this paper, the phenomenon of intergranular fracture in polycrystalline materials is investigated using a nonlinear fracture mechanics approach. The nonlocal cohesive zone model (CZM) for finite thickness interfaces r...