In this paper parallel manipulators, consisting of a basic antropomorph kinematic chain and parallel chains with redundant in number linear actuators are investigated. Antagonistic stiffness, as a result of the actuation redundancy is also studied. A kinematic model of parallel manipulators and a stiffness model are created. Conditions for specification of the antagonistic stiffness are conside...

In this paper, a novel mechanism of remote actuation was proposed and its mechanical problems were discussed. This mechanism consists of leverage and parallelogram mechanism and transmits 3 d.o.f translational and 3 d.o.f rotational motions from the input to output. Such a remote actuation is significantly useful for robotic assist around MRI where the strong and precise magnet is used for imag...

Starting from the hypothesis that the tubulin dimer is a conformationally bistable molecule fluctuating between a curved and a straight configuration at room temperature we develop a model for polymorphic dynamics of the microtubule lattice. We show that tubulin bistability consistently explains unusual dynamic fluctuations, the apparent length-stiffness relation of grafted microtubules and the...

Large protein assemblies, such as virus capsids, may be coarse-grained as a set of rigid units linked by generalized (rotational and stretching) harmonic springs. We present an ab initio method to obtain the elastic parameters and overdamped dynamics for these springs from all-atom molecular-dynamics simulations of one pair of units at a time. The computed relaxation times of this pair give a c...

Stability of the spinal column is critical to bear loads, allow movement, and avoid injury and pain [1]. Recently, the analogy of “Six Blind Men and the Elephant” has been used to describe a chasm that exists between different definitions and approaches employed to quantify spine stability [2], with the outcome being that different methods are used without a clear understanding of how they rela...

This paper presents nonlinear elastic dynamic analysis of 3-D semi-rigid steel frames including geometric and connection nonlinearities. The geometric nonlinearity is considered by using stability functions and updating geometric stiffness matrix. The nonlinear behavior of the steel beam-to-column connection is considered by using a zero-length independent connection element comprising of six t...

We present the Hbot, a holonomic, singularity-free spherical robot designed for haptic simulations. The Hbot is made up of a caged sphere actuated by steered and driven nonholonomic wheels to produce continuous and unlimited spherical motions. We analyse the kinematic interface between a sphere and n arbitrarily positioned, steered and driven non-holonomic wheels in the general case. We also pr...

This paper presents an air bearing stage that uses flexure for yaw motion compensation. The proposed realizes in three degrees of freedom (DOF), which are the X, Y, and Θz directions. To work with as rotational stage, we applied a consisting four bar linkages. from previous study is to compensate error has limitation increasing structural stiffness due stiffness. In this study, propose combinat...

In this study, the monotonic and cyclic behavior of an offshore wind turbine with a monopile foundation installed in sand layer were evaluated centrifuge. A simplified was modeled, lateral load applied to tower under displacement control. The loading test ultimate capacity bending moment profiles different levels. During loading, variations moment-rotation responses, stiffness, moments along pi...

This paper presents a unified approach to vibration analysis of functionally graded beams with transverse open-edge cracks based on the so-called shape obtained as general solution equations in frequency domain. The crack is modeled by pair translational and rotational springs stiffness computed from depth dependence upon material parameters. frequency-dependent functions allow one not only obt...