Underground tunnel face bolting and pipe umbrella reinforcement are one of the most challenging tasks in construction whether industrial or not, and infrastructures such as roads or pipelines. It is one of the first sectors of economic activity in the world. Through a variety of soil and rock, a cyclic Conventional Tunneling Method (CTM) remains the best one for projects with highly variable gr...

For an induction machine, we suggest a theoretical development of the mechanical unbalance effect on the analytical expressions of radial vibration and stator current. Related spectra are described and characteristic defect frequencies are determined. Moreover, the stray flux expressions are developed for both axial and radial sensor coil positions and a substitute diagnosis technique is propos...

OBJECTIVE Occupational use of vibrating hand tools contributes to the development of upper extremity disorders. While several types of vibration damping materials are commercially available, reductions in vibration exposure are usually tested in the laboratory rather than in actual work environments. This study evaluated reductions in hand vibration with different vibration damping intervention...

One source of structural vibration in a submarine is the fluctuating axial thrust force applied to the thrust block by the propeller shaft. This paper describes the initial stages of experimental work being undertaken to validate an existing mathematical model for the sound radiation from a submarine excited by this mechanism. A thin cylindrical shell 1500mm long and 400mm in diameter made of 2...

The vibration characteristics of piezoelectric hollow-disc transducers were investigated in this paper. It was assumed that the vibration modes were coupled in the axial and radial directions. Theoretically the differential equations of piezoelectric motions were derived in terms of the axial and radial displacements and the electric potential. Solutions of the boundary value problem yielded th...

in this paper, a simple and efficient method for modeling and solving the equations of a rotor with any number of disks, bearings and mass unbalances is presented using the assumed modes method. this model consists of a continuous shaft, arbitrary number of mass unbalances in any axial location and phase angle, and any number of rigid disks and bearings. this arrangement is extensively used in ...

this paper presents the thermal vibration analysis of double-layer graphene sheet embedded in polymer elastic medium, using the plate theory and nonlocal continuum mechanics for small scale effects. the graphene is modeled based on continuum plate theory and the axial stress caused by the thermal effects is also considered. nonlocal governing equations of motion for this double-layer graphene s...

Heavy vehicle truck transmission gearbox housing is subjected to load fluctuations, harmonic excitation, gear meshing excitation, gear defects, varying speed and torque conditions. Transmission errors and internal excitations are the root cause of vibration and noise. The main objective of this research work is weight calculation and modal analysis of gearbox housing. For weight calculation fou...

Real-world whole-body vibration exposures comprise motion in fore-aft, lateral, and vertical directions simultaneously. There can also be components of roll, pitch, and yaw. If evaluating vibration with respect to human response, most investigators will use methods defined in ISO 2631-1. This uses frequency weightings that were originally derived from laboratory studies of the subjective respon...