Rigid-perfectly plastic

The material is assumed as rigid-perfectly plastic, i.e. no strain-hardening effects are taken into consideration. 

Fig. 14. Asymptotic, interface-comer slip-line solution for a perfectly plastic quarter plane bonded to a rigid substrate.

Fig. 29. Comparison of elastic-perfectly plastic finite-element and asymptotic solutions for normal stress for a thin layer on a rigid substrate subjected to uniform cooling.

A simple way to appreciate the shape of fullerene is to construct a physical model in which rigid planar trivalent nodal connectors represent the atoms and flexible plastic bars (tubes) of circular cross-section represent the bonds. From a mechanical point of view the model may be considered as a polyhedron-like space frame whose equilibrium shape is due to self-stress caused by deformation of bars. We suppose that the bars are equal and straight in the rest position and that they are inclined relative to each other at every node with angle of 120°. The material of the bars is assumed to be perfectly elastic and that Hooke s law is valid. All the external loads and influences are neglected and only self-stress is taken into account. Then we pose the question What is the shape of the model subject to these conditions To answer this question we apply the idea used for coated vesicles by Tarnai Gaspar (1989). 

G-lf the pipe line is plastic or steel, this design, although less perfect than F.may be used. It holds the pipe rigidly in place to prevent movement but relies for membrane tightness on the seal at the internal notch so that any leakage at that point can enter the concrete along the shaft. 

Their characterization could not, in this context, be further from the truth. Metis, far from being rigid and monolithic, is plastic, local, and divergent. It is in fact the idiosyncracies of metis, its contextualness, and its fragmentation that make it so permeable, so open to new ideas. Metis has no doctrine or centralized training each practitioner has his or her own angle. In economic terms, the market for metis is often one of nearly perfect competition, and local monopolies are likely to be broken by innovation from below and outside. If a new technique works, it is likely to find a clientele. 

In-place trimming is most effective with thin sheet (<1 mm) and narrow sheet. The advantages of in-place trimming are that the trim die acts as a cavity isolator the formed products remain in the mold cavity and are therefore in perfect registry the plastic is soft and, as a result, the trim forces are low and there is often less trim dust. The trim die is usually a hardened steel rule that is rigidly mounted in a plate that is integral to the mold structure. 

---