This paper demonstrates the use of potential functions of molecular modeling in mass-spring systems. In mass-spring systems, force acting on each mass point is determined by the spring length between linked mass-points. In molecular modeling, forces are calculated using bond length (spring length), bond angle and stretch-bond interactions. Molecular modeling therefore provides more accurate for...

The biomechanical determinants of the scaling of chew cycle duration are important components of models of primate feeding systems at all levels, from the neuromechanical to the ecological. Chew cycle durations were estimated in 35 species of primates and analyzed in conjunction with data on morphological variables of the feeding system estimating moment of inertia of the mandible and force pro...

3 Simulation Phase: Three Models for Simulation 9 3.1 3D ChainMail . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 3.2 Mass Spring Models . . . . . . . . . . . . . . . . . . . . . . . 13 3.2.1 Classical Mass Spring Model . . . . . . . . . . . . . . . 13 3.2.2 Fast Tetrahedral Mass Spring Model . . . . . . . . . . 15 3.3 Finite Element Models . . . . . . . . . . . . . . . . . . . . . . 1...

This paper discusses two approaches to modeling helical suspension springs for use in a dynamic finite element compressor model. The first approach represents the spring's stiffness characteristics with a simple spring element matrix. The appropriate spring constants are calculated using a separate finite element model of the spring. The spring modeling procedure is described and supplemented w...

The set of coordinates used to describe the motion of a dynamic system is not unique. For example, consider an elastic pendulum (a mass on the end of a spring). The position of the mass at any point in time may be expressed in Cartesian coordinates (x(t), y(t)) or in terms of the angle of the pendulum and the stretch of the spring (θ(t), u(t)). Of course, these two coordinate systems are relate...

In this paper, we propose a stable and efficient algorithm for animating mass-spring systems. An integration scheme derived from implicit integration allows us to obtain interactive realistic animation of any mass-spring network. We alleviate the need to solve a linear system through the use of a predictor-corrector approach: We first compute a rapid approximation of the implicit integration, t...

This paper proposes a new fundamental model of deformable objects for real-time and interactive applications. It is based on the mass-and-spring model, but in which the unit of elastic force definition for computation of dynamics is expanded from a spring to a volume element divided by the boundaries formed by mass-and-spring lattice. Displacements of the vertices of the volume element are defi...

This paper documents the mechanical system of the Electric Cable Differential leg, and its incorporation into a monopod hopping robot named Thumper and a bipedal robot named MABEL. The ECD Leg is designed with physical springs and other passive dynamics to match a mathematically simple, bio-inspired mass-spring model, which can exhibit robust and economic walking and running gaits. With this de...

The set of coordinates used to describe the motion of a dynamic system is not unique. For example, consider an elastic pendulum (a mass on the end of a spring). The position of the mass at any point in time may be expressed in Cartesian coordinates (x(t), y(t)) or in terms of the angle of the pendulum and the stretch of the spring (θ(t), u(t)). Of course, these two coordinate systems are relate...

Dr. Constance E. Ruhl is an Epidemiologist at Social & Scientific Systems, Inc., Silver Spring, MD. Dr. Jeanne M. Clark is a Professor of Medicine and Epidemiology and Director of the Division of General Internal Medicine at The Johns Hopkins University, Baltimore, MD. Dr. James E. Everhart was Chief of the Epidemiology and Clinical Trials Branch in the Division of Digestive Diseases and Nutrit...