Abstract In this article, we present a dynamic model for generic drill-string. The is developed with the intention component-based simulation coupling to external subsystems. performance of drill-string vital in terms efficient wellbore excavation increased hydrocarbon extraction. Drill-string vibrations limit rotary drilling; phenomenon well known and still subject interest academia industry. ...

This study proposes a method to reduce car body elastic vibrations in bullet trains caused by longitudinal excitation via traction devices and yaw dampers. We devised two vibration reduction devices—"displacement-dependent rubber bushes" "mesh springs" suppress the force. conducted tests using Shinkansen (bullet train) type test vehicle rolling stock testing plant examine running stability supp...

We solved the problem of finding longitudinal acoustic directions of monoclinic media using the eliminant method. By extending Khatkevich’s approach and using the Bezout theorem, we proved that the number of longitudinal normals for mechanically stable monoclinic media can not be larger than 13. Both longitudinal normals (n1, n2, n3) lying in and out of plane perpendicular to the two-fold axis ...

Assassin bugs (Stenolemus bituberus) hunt web-building spiders by invading the web and plucking the silk to generate vibrations that lure the resident spider into striking range. To test whether vibrations generated by bugs aggressively mimic the vibrations generated by insect prey, we compared the responses of spiders to bugs with how they responded to prey, courting male spiders and leaves fa...

this paper deals with new method for designing the tuned mass dampers (tmd) with considering both transient and steady state responses, simultaneously. this formulation is presented for undamped vibrations. for this purpose, the absolute value of the structural displacement ratio is minimized numerically. this procedure leads to optimum value of tmd's specifications. for numerical verification,...

This research focuses on the analysis of model and performance lightweight metastructures encompassing a distributed array internal homogenous oscillators, integrated into host structure to create single-piece element. metastructure performs longitudinal vibrations, whose axis is colinear with direction transverse vibration oscillators. First, mechanical models separate elements as whole are cr...

In this study, a low degree-of-freedom mechanical model of a rolling tire is constructed, in which the lateral deformation of the contact patch and tire carcass is considered. The so-called delayed contact patch model is implemented and combined with a simple tire carcass model. The interaction between the contact patch and the carcass together with the lateral mode of the attached suspension s...

We consider an optimal boundary control problem for a one-dimensional wave equation consisting of two non-homogenous segments with piecewise constant characteristics. The describes the longitudinal vibrations non-homogeneous rod or transverse string given initial, intermediate, and final conditions. assume that travel time each sections is same. carried out by shifting one end other fixed. qual...