In this paper we present a new digital ultrasonic instrument for nondestructive inspection of rock bolts using guided waves. The Rock Bolt Tester (RBT) instrument applies long-range ultrasound to investigate bolt’s status, especially its grouting condition. RBT features an application tailored ultrasound probe that transmits high-energy, low frequency (below 100kHz) guided waves and is capable ...

Following the Northridge earthquake of 1994, a significant number of steel moment resisting structural systems were damaged. Several studies have been conducted to improve the seismic performance of steel structures and specially their beam-to-column connections. One of the proposed connections for special moment-resisting frames included AISC-358 is Kaiser bolted bracket moment connection, bri...

modeling and wrench feasible workspace analysis of a spatial cable suspended robots is presented. a six-cable spatial cable robot is used the same as stewart robots. due to slow motion of the robot we suppose the motion as pseudostatic and kinetostatic modeling is performed. various workspaces are defined and the results of simulation are presented on the basis of various workspaces and applied...

Workspace analysis is one of the most important issues in the robotic parallel manipulator design. ‎However, ‎the unidirectional constraint imposed by cables causes this analysis more challenging in the cabledriven redundant parallel manipulators. Controllable workspace is one of the general workspace in the cabledriven redundant parallel manipulators due to the dependency on geometry parameter...

Stress grading (SG) layer in cable terminations limits the critical electric field and properties of SG materials are important issues which have to be considered during manufacturing and selecting procedure. In this paper, two different types of (SG) materials are analyzed by both theory and test. According to the applied theory, important parameters as: electrical resistivity, breakdown volta...

Cables have always been under consideration as a structural element because of important features such as large strength to weight ratios and long spans. Their equilibrium analysis is an important issue in this regard. But this analysis involves highly nonlinear equations arising from large deformations and material nonlinearity. Different methods have been under use for numerical analysis of s...

this paper proposes a control strategy for a cable-suspended robot based on sliding mode approach (smc) which is faced to external disturbances and parametric uncertainties. this control algorithm is based on lyapunov technique which is able to provide the stability of the end-effecter during tracking a desired path with an acceptable precision. the main contribution of the paper is to calculat...

Abstract This paper designed a special-shaped cross-section hollow self-drilling bolt with discharge grooves, in which Mindlin’s solution of displacement was used the elastic wholly grouted bolt. Theoretically, ultimate pulling force and residual were analyzed by considering average distribution assumption stress. The bolts’ performance 2, 3, 4 grooves compared circular bolts, experimental resu...