The research leading to this paper was prompted by the need to estimate strength and stiffness of Rigid Rocking Cores (RRCs) as essential elements of resilient earthquake resisting structures. While a limited number of such studies have been reported, no general study in terms of physical properties of RRCs, their appendages and adjoining structures have been published. Despite the growing know...

The nonlinear dynamics of rocking rigid bodies with simple geometries, such as rectangular blocks and cylinders, have been the focus community over last six decades. However, many objects that are prone to or overturning do not conform geometries. These include museum artifacts precariously balanced rocks in natural world. Even cases where response body is planar, geometry much more complicated...

We study the problem of propagating longitudinal waves in an elastic rod connected to a locally damaged foundation through thin layer. The motion rigid blocks is considered predetermined. formulated initial-boundary for Klein?Gordon equation with discontinuous right-hand side. nonstationary fields displacements, velocities, and deformations were investigated by Laplace integral transformation m...

AIM Many studies are available in the literature on posterior spinal instrumentation, though the use of a rod and a plate is still controversial in the literature. In this study, a finite element analysis of the strength and superiority of modular rigid plate and rod systems, which are used in the lower lumbar region, in comparison with each other was used. MATERIAL AND METHODS A Ti6Al4V (Gra...

Long time ago to calculate back-reaction of electromagnetic field on moving with acceleration a charged classical (not quantum) particle of finite size Sommerfeld [1] considered two models uniformly charged rigid sphere and uniformly charged rigid ball and found out explicit expressions for electromagnetic self-forces. These expressions in nonrelativistic limit are much simpler then the origina...

This article conducts mechanical analysis of billiards and studies its motion laws. For convenience, only situations as the ball arm bats the billiards in the horizontal direction are considered. Besides, collision between one billiard ball and another or between a ball and the “KEXING” is assumed to be elastic. The following cases are quantitatively analyzed based on the rigid body dynamics th...

this paper evaluates a new and simple controller design method based on qft (quantitative feedback theory) for a two-link manipulator whose first link is rigid and the second is flexible. a piezoelectric patch is attached to the surface of the flexible link for vibration suppression of it. this system is modeled as a nonlinear multi-input multi-output (mimo) control systems whose inputs are two...

BACKGROUND Many decompression procedures involve complete or partial facetectomy. Spinal fusion usually stabilizes the motion segment after complete facetectomies. However, problems with fusion, such as adjacent-level degeneration, have increased interest in motion- preservation technologies. Facet arthroplasty may become an important posterior motion-preservation device, but its biomechanical ...