The metabolic cost of running is substantial, despite the savings from elastic energy storage and return. Previous studies suggest that generating vertical force to support body weight and horizontal forces to brake and propel body mass are the major determinants of the metabolic cost of running. In the present study, we investigated how independently altering body weight and body mass affects ...

leads to a sequence of BVPs for φn in the unperturbed domain (r > a); φ0 is the unperturbed solution and subsequent φn are forced by φm with m < n. The idea behind the boundary perturbation technique is old and familiar. For example, it is used in the theory of small-amplitude water waves, wherein the nonlinear boundary conditions on the (unknown) free surface z = F (x, y) are ‘linearized’ abou...

The dynamics of pectoral fin rowing in the threespine stickleback are investigated by measuring the instantaneous force balance on freely swimming fish throughout the stroke cycle and comparing the measured forces with fin motions and an unsteady, blade-element model of pectoral fin propulsion. Both measured and modeled forces suggest that attached vortex and circulatory forces and not inertial...

Recent studies have demonstrated that a quasi-steady model closely matches the instantaneous force produced by an insect wing during hovering flight. It is not clear, however, if such methods extend to forward flight. In this study we use a dynamically scaled robotic model of the fruit fly Drosophila melanogaster to investigate the forces produced by a wing revolving at constant angular velocit...

A detailed investigation into the analysis of beams with different boundary conditions. carrying either a moving mass or force is performed. Analytical and numerical techniques for determination of the dynamic behavior of beams due to a concentrated travelling force or mass are presented. The transformation of the familiar Euler-Bernoulli thin beam equation into a series of ordinary differentia...

The dynamics of particle–particle collisions in a viscous fluid are numerically investigated. A distributed-Lagrange-multiplier-based computational method in a solid-fluid system is developed and a collision strategy for general shape objects is presented. In earlier methods, a repulsive force is applied to the particles when their separation is less than a critical value and, depending on the ...

An analytical approach is presented to assess the response of offshore structures under seismic excitation. This paper evaluates the impacts of different fluid field models and the mass of equipment at the top of offshore structure which is simulated as lumped mass on the responses of offshore structures. To do this, two and three dimensional fluid field models are developed. In three dimension...