In Reference [1] the authors have shown that numerical differentiation is a competitive alternative to analytical derivatives for the computation of consistent tangent matrices. Relatively simple models were treated in that reference. The approach is extended here to a complex model: the MRS-Lade model [2,3]. This plastic model has a cone-cap yield surface and exhibits strong coupling between t...

We discuss software tool support for the Algorithmic Differentiation (also known as Automatic Differentiation; AD) of numerical simulation programs that contain calls to solvers for parameterized systems of n nonlinear equations. The local computational overhead as well as the additional memory requirement for the computation of directional derivatives or adjoints of the solution of the nonline...

The stiffness of micron-sized sphere-plate contacts was studied by employing high frequency, tangential excitation of variable amplitude (0-20 nm). The contacts were established between glass spheres and the surface of a quartz crystal microbalance (QCM), where the resonator surface had been coated with either sputtered SiO2 or a spin-cast layer of poly(methyl methacrylate) (PMMA). The results ...

Our previous experimental results (A. M. Boriek, S. Lui, and J. R. Rodarte. J. Appl. Physiol. 75: 527-533, 1993 and A. M. Boriek, T. A. Wilson, and J. R. Rodarte. J. Appl. Physiol. 76: 223-229, 1994) showed that 1) costal diaphragm shape is similar at functional residual capacity and end inspiration regardless of whether the diaphragm muscle shortens actively (increased tension) or passively (d...

Hygrothermal analysis of laminated composite plates has been done by using an efficient higher order shear deformation theory. The stress field derived from hygrothermal fields must be consistent with total strain field in this type of analysis. In the present formulation, the plate model has been implemented with a computationally efficient C0 finite element developed by using consistent strai...

A Monte Carlo code applied to the cgDNA coarse-grain rigid-base model of B-form double-stranded DNA is used to predict a sequence-averaged persistence length of lF = 53.5 nm in the sense of Flory, and of lp = 160 bp or 53.5 nm in the sense of apparent tangent-tangent correlation decay. These estimates are slightly higher than the consensus experimental values of 150 bp or 50 nm, but we believe ...

Realistic animation and rendering of the metal shell is an important aspect for movies, video games and other simulators. Usually this is handled by FEMmethod, which requires extremely high computational cost due to solving the stiffness matrix. We now propose a trick that could smartly avoid the large scale computation required by FEM, and could still generate visually convincing images of met...

An explicit construction of a geodesic flow-invariant distribution lying in the discrete series of weight 2k isotopic component is found, using techniques from representation theory of SL2(R). It is found that the distribution represents an AC measure on the unit tangent bundle of the hyperbolic plane minus an explicit singular set. Finally, via an averaging argument, a geodesic flow-invariant ...