HAMILTONIAN STRUCTURE FOR RIGID BODY WITH FLEXIBLE ATTACHMENTS IN A CIRCULAR ORBIT

Hamiltonian structure of a rigid body in a circular orbit is established in this paper. With the reduction technique, the Hamiltonian structure of a rigid body in a circular orbit is derived from Lie-Poisson structure of semidirect product, and Hamiltonian is derived from Jacobi's integral. The above method can be generalized to establish the Hamiltonian structure of a rigid body with a flexible attachment in a circular or- bit. At last, an example of stability analysis is given.

Equilibrium Positions of a Cable-Connected Satellites System under Several Influences

The present paper deals with the study of equilibrium positions of the motion of a system of two artificial satellites connected by a light, flexible, inextensible and non-conducting cable under the influence of solar radiation pressure, earth’s oblateness, shadow of the earth and air resistance. Here, we study the case of circular orbit of the centre of mass of the system. We derive differential equations of motion of the system. General solutions of the differential equations are beyond the reach. On the other hand, the general solutions do not serve our purpose. Jacobian integral of the system has also been obtained. Thereafter equilibrium positions of the motion of the system have been obtained.

Analysis of Stress and Strain Fields of Laser Cladding Process on Ring Circular Orbit

The cracking of coatings and the deformation of base frustrate the application of laser cladding technology especially on surface of the ring circular orbit.In order to solve the two problems above,the stress and strain fields of the laser cladding process on the ring circular orbit were analyzed through the finite-element method,based on the temperature field.The wedge module of the ring circular ring was the subject investigated. The calculating results show that during the cladding process the crank point tends to generate the transversal crack;the centre point on the coating/base interface tends to generate longitudinal crack;the intersecting edge of the coating and base tends to generate toe crack.Moreover,the cracking tendency of the outer marginal point is obviously greater than that of the inner marginal point.The rather high stress appears at the border position where the constraint exists,and the stress on the point in front of molten pool under the range of laser irradiation is large as well.And the displacement becomes larger as the cladding process proceeds.

Astrophysical observables for regular black holes with sub-Planckian curvature

We investigate the photon sphere and marginally stable circular orbit of massive particles over the re-cently proposed regular black holes with sub-Planckian curvature and a Minkowskian core.We derive the effective potential for geodesic orbits and determine the radius of circular photon orbits,with an analysis of the stability of these orbits.We extend our analysis to the background of a compact massive object(CMO)without a horizon,whose mass is below the lowest bound for the formation of a black hole.For massive particles,marginally stable cir-cular orbits become double-valued in the CMO phase.Through a comparison with Bardeen and Hayward black holes,we also find that the locations of the photon sphere and marginally stable circular orbit in the CMO phase with a Minkowskian core are evidently different from those in the CMO phase with a dS core,which potentially provides a way to distinguish between these two types of black holes by astronomical observation.Finally,we present the ob-servational constraint on the deviation parameter for such regular black holes using observed data from the black hole M87^(*).