Pre-stress degradation or looseness of rock bolts in mining or tunnel engineering threatens the stability and reliability of the structures. In this paper, an innovative piezoelectric device named a "smart washer" with the impedance method is proposed with the aim of developing a real-time device to monitor the pre-stress level of rock bolts. The proposed method was verified through tests on a ...

Steel-concrete-steel (SCS) sandwich panels are composed of two steel plates with low thicknesses and high densities and strengths and one thick layer between both plates with low strength and density known as core that is composed of concrete. Cohesive material-epoxy resin or shear connectors are usually used to connect the plates to the concrete core. SCS sandwich composites are being develope...

This paper presents a series of tests on cold-formed stainless steel bolted connections. The test specimens were fabricated from three different types of stainless steel, including austenitic stainless steel EN1.4301 (AISI 304) and EN1.4571 (AISI 316Ti having small amount of titanium) as well as lean duplex stainless steel EN1.4162 (AISI S32101). The material properties of the three types of st...

Rock bolts ensure structural stability for tunnels and many other underground structures. The pre-load on a rock bolt plays an important role in the structural reinforcement and it is vital to monitor the pre-load status of rock bolts. In this paper, a rock bolt pre-load monitoring method based on the piezoceramic enabled time reversal method is proposed. A lead zirconate titanate (PZT) patch t...

The engine mount transmission force can be used as an important basis to evaluate the vibration isolation performance of mounting system. However, there is a lack testing equipment and methods for force. sensor test method studied. finite element model established analyze arrangement position sensor. developed based on resistance strain gauge. arranged in middle intermediate bolt. system at sam...

in this research, the influence of bolt preload on the fatigue strength of 2024-t3 aluminium alloy double lap bolted joints has been studied experimentally and numerically. to do so, three sets of the specimens were prepared and each of them subjected to tightening torque of 1,2.5 and 5 n-m and then fatigue tests were conducted under various cyclic axial load levels. in the numerical method, th...

OBJECTIVES The Sliding Hip Screw (SHS) is commonly used to treat trochanteric hip fractures. Fixation failure is a devastating complication requiring complex revision surgery. One mode of fixation failure is lag screw cut-out which is greatest in unstable fracture patterns and when the tip-apex distance of the lag screw is > 25 mm. The X-Bolt Dynamic Hip Plating System (X-Bolt Orthopaedics, Dub...

For many years U.S. design codes modeled the design values of a multiple-bolt joint as the design value of a single-bolt connection multiplied by the number of bolts. The provisions were based on research conducted by Trayer (1932) who observed an equal distribution of load among bolts. This was despite the fact that research conducted as early as in the late 19 century suggested an uneven load...

this paper presents the results of the assembly process of a gasketed bolted flanged pipe joint for two different bolt tightening strategies, i.e. asme and industrial using torque control of preload method.  the final clamping force is achieved in four and five passes in asme and industrial strategy respectively. axial bolt stress variation, at the end of each pass, individual bolt bending beha...

Conventional bolt–shotcrete support technology is usually single-layered, which does not meet the requirements of strength and stiffness for roadway support. Therefore, in this paper, new combined technology, including a multiple-layered staggered dense arrangement bolts, laying steel meshes, pouring shotcrete, strengthening long cables, full cross-section grouting, proposed. Specifically, foll...