Macroscopical Modeling and Numerical Simulation for the Characterization of Crack and Durability Properties of Particle-Reinforced Elastomers

Numerical modeling of particle-reinforced or filled elastomers is a challenging task and includes the adequate representation of finite deformations, nonlinear elasticity, local damage as well as rate-dependent and rate-independent dissipative properties. On the structural scale, the permanent alteration of the material is visible as formation and propagation of discrete cracks, especially in the case of catastrophic crack growth and fatigue crack propagation. In this chapter, macromechanically formulated material models for finite viscoelasticity and endochronic elasto-plasticity of filled elastomers are presented in order to describe the material response of the undamaged continuum. On the FE-discretized structural scale, crack sensitivity of the material is assessed by the material force method. Material forces are used for the computational determination of fracture mechanical parameters of dissipative rubber material. Finally, arbitrary crack growth on the structural level is addressed by an adaptive implementation of cohesive elements. In a first application, crack propagation starting from an initial side notch in a tensile rubber specimen under mixed-mode loading is numerically predicted and compared to experimental observations. In a second example, averaged stress and energy based criteria are studied and compared with respect to their crack path predictability. In a third example, the durability of a tire design is numerically assessed by using the material force method

Landscapes of Desire: Tourists, Touts and Sexual Encounters at the World Heritage Site of Thebes

Cultural tourism capitalises on archaeological sites with World Heritage status on a global scale. The encounters of visitors from all over the world with local residents and other stakeholder groups, like local and international entrepreneurs, set off complex processes of interaction in which the physical and social space of the heritage site is negotiated, shaped and consumed. In a case study from Luxor/Egypt, this paper investigates a particular facet of these interactions, namely sexual encounters between tourists and members of the local community. It delineates the economic and social conditions of this phenomenon and discusses the role it takes in the production, perception and use of the World Heritage site of Thebes. © 2013 World Archaeological Congress