This paper reports a simple and flexible method for generating hierarchical patterns from wrinkling instability. Complex features with gradually changing topographies are generated by using the spontaneous wrinkling of a rigid membrane (titanium) on a soft foundation (polystyrene) compressed via the diffusion of a solvent. We show that the morphology of these unreported wrinkled patterns is dir...

Abstract: This paper is concerned with a shape optimization problem of a viscoelastic body in unilateral dynamic contact with a rigid foundation. The contact with Coulomb friction is assumed to occur at a portion of the boundary of the body. The nonpenetration condition is described in terms of velocities. The thermal deformation is taken into account. Using the material derivative method as we...

We consider numerical approximations of a quasistatic problem modeling the sliding frictional contact with wear between a viscoelastic body and a rigid moving foundation. The contact is modeled with the Coulomb's law of dry friction and the wear is described by a version of Archard's law. The variational formulation of the problem consists of a nonlinear evolutionary equation coupled with a tim...

We investigate the unique mechanical properties of reentrant 3D origami structures based on the Tachi-Miura polyhedron (TMP). We explore the potential usage as mechanical metamaterials that exhibit tunable negative Poisson's ratio and structural bistability simultaneously. We show analytically and experimentally that the Poisson's ratio changes from positive to negative and vice versa during it...

Existence of a weak solution for the problem of dynamic frictional contact between a viscoelastic body and a rigid foundation is established. Contact is modelled with the Signorini condition. Friction is described by a slip rate dependent friction coefficient and a nonlocal and regularized contact stress. The existence in the case of a friction coefficient that is a graph, which describes the j...

We have investigated the microsecond rotational dynamics of F-actin with transient phosphorescence anisotropy (TPA) spectroscopy, and analyzed the data to determine the relative contributions from rigid-body rotations and from intrafilament bending and twisting, using a theoretical model developed for DNA dynamics by Schurr and co-workers. The fits of the data to the model were constrained by i...

We prove both in the smooth and discrete setting that the Hessian of an elastic deformation energy results in a proper Riemannian metric on the space of shells (modulo rigid body motions). Based on this foundation we develop a timeand space-discrete geodesic calculus. In particular we show how to shoot geodesics with prescribed initial data, and we give a construction for parallel transport in ...

It is often claimed that Kripke (1980) and Putnam (1975) established that many predicates, most importantly natural kind predicates, are like proper names in being rigid designators. This insight is generally regarded as having important consequences in the theory of necessary truths: the rigidity of terms such as 'Hesperus', 'Phosphorus', 'water' and 'H 2 O' is used in explaining why identity ...

This paper describes QLB, a quantified logic of belief that is a possible extension of the modal system KD45n to predicate level. The main features of QLB are that: (i) it is allowed to quantify over the agents of belief; (ii) the belief operator can be indexed by any term of the formal language; (iii) terms are not rigid designators, but are interpreted contextually; (iv) automatic theorem pro...

field observations of the incurred damages to the buildings and bridges due to earthquakes in near field show there are various failure modes which are in relation to the forces caused by vertical component. while vertical component of earthquake for ordinary buildings in most seismic regulations and standards is not considered. therefore, in the current study the effects of vertical and horizo...