In order to solve the problems of roadway stability and easy instability under repeated mining close-distance coal seam groups, mechanism control technology surrounding rock were studied via indoor testing, field physical similarity simulation experiment, numerical simulation. The results show that has low strength, bearing capacity, poor self-stabilization ability, it is vulnerable engineering...

in this paper robust pid control of fully-constrained cable driven parallel manipulators with elastic cables is studied in detail. in dynamic analysis, it is assumed that the dominant dynamics of cable can be approximated by linear axial spring. to develop the idea of control for cable robots with elastic cables, a robust pid control for cable driven robots with ideal rigid cables is firstly de...

Two types of lapped transforms have been studied in detail in the literature, namely, the lapped orthogonal transform (LOT) and its extension, the biorthogonal lapped transform (BOLT). In this paper, we will study the lapped unimodular transform (LUT). All three transforms are first-order matrices with finite impulse response (FIR) inverses. We will show that like LOT and BOLT, all LUTs can be ...

The Lapped Orthogonal Transform (LOT) [ I ] is a popular transform and has found many applications in signal processing. Its extension, BiOrthogonal Lapped Transform (BOLT), has been investigated in detail in [2]. In this paper, we will study Lapped Unimodular Transform (LUT). All of these three transforms are first-order matrices with FIR inverses. We will show that like LOT and BOLT, all LUTs...

Frame stability in Ilizarov external fixators is mainly dependent on the tension of the transosseous wires, which are clamped to the ring by connection bolts. It was the purpose of this biomechanical study to investigate the holding capacity of a modified bolt design featuring a ruffled wire-bolt interface (TrueLok™) and its influence on wire stiffness in comparison with that of classic bolts f...

Rock bolts have been widely used as rock reinforcing members in underground coal mine roadways and tunnels. Failures of rock bolts occur as a result of overloading, corrosion, seismic burst and bad grouting, leading to catastrophic economic and personnel losses. Monitoring the health condition of the rock bolts plays an important role in ensuring the safe operation of underground mines. This wo...

Aiming at the problems of difficult support mining roadway under goaf close distance coal seam, obvious large deformation, and long-term continuous deformation surrounding rock, an advanced bolt-grouting system is proposed. The can effectively solve problem from design system, construction monitoring evaluation realize intelligent support. Based on actual engineering background 29204 working fa...

Abstract Numerical simulation is a useful tool in investigating the loading performance of rock bolts. The cable structural elements (cableSELs) FLAC3D are commonly adopted to simulate bolts solve geotechnical issues. In this study, bonding interface between bolt and grout material was simulated with two-stage shearing coupling model. Furthermore, FISH language used incorporate shear model into...

Introduction In the distant past large animals were sometimes stunned by a heavy blow on the head where poultry was decapitated before slaughter During the last century concern for animal welfare increased. Concussion stunning was deemed not satisfactory, and improved stunning methods were developed. Stunning by captive bolt was introduced at the end of the 19th century, electrical stunning at ...