Resonant Sonic Head drilling (RSHD) induces axial vibrations along the drillstring system which affect the accuracy and quality of pre-reinforcement required to tunnels excavation in complex soils. The main goal of this paper is to control these vibrations in order to improve this process. First, an infinite dimensional equations as vibration model are elaborated with Neumann boundary condition...

In this research, finite element analysis of the conventional drilling and vibration assisted drilling is carried out. The ABAQUS software is employed for FE analysis. The Johnson-Cook models for both plastic deformation and damage are employed for FE simulation.The results of the FE analysis are then verified with experimental results in both conventional and vibration assisted drilling on Al ...

axial vibration effect of shell particles on dynamic stability of a cantilevered cylindrical shell under an axial follower force was addressed. in spite of free-ended shells, the reduced axial force under this effect cannot be derived analytically. instead, an approximate method was proposed based on the fact that the static (and harmonic) axial deformation under an axial load in a free-ended b...

Turbomachinery shafting and casings typically experience axial growth during thermal transients occurring at startup, shutdown, and changes of load. This growth does not usually present difficulties during operation. However, this paper discusses four recent turbomachinery trains that experienced radial subsynchronous vibration resulting from axial misalignment. In each example, the train inclu...

the use of bio-ethanol as an alternative diesel engine fuel is rapidly increasing. bio-ethanol is mixed with diesel fuel at different ratios and used in ci and si engines. since vibrations have direct effects on users and engine components, for this reason analysis of vibration resulting from combustion in ci engines is very important. in this study, evaluation of vibration was performed for bo...

In this research, finite element analysis of the conventional drilling and vibration assisted drilling is carried out. The ABAQUS software is employed for FE analysis. The Johnson-Cook models for both plastic deformation and damage are employed for FE simulation.The results of the FE analysis are then verified with experimental results in both conventional and vibration assisted drilling on Al ...

The main purposes of the present work are devoted to the investigation of the free axial vibration, as well as the time-dependent and forced axial vibration of a SWCNT subjected to a moving load. The governing equation is derived through using Hamilton's principle. Eringen’s nonlocal elasticity theory has been utilized to analyze the nonlocal behaviors of SWCNT. A Galerkin method based on a clo...

The generalized differential quadrature (GDQ) method is used to obtain the computational results of two-layer cross-ply laminated shell under rapid uniform heat induced vibration. In the thermally insulated vibration analyses of a laminated shell, the sudden uniform heat input over its lower surface only and temperature load is linear of axial coordinate. The GDQ method provides a method for ca...

Thisstudy presents axially forced vibration of a cracked nanorod under harmonic external dynamically load. In constitutive equation of problem, the nonlocal elasticity theory is used. The Crack is modelled as an axial spring in the crack section. In the axial spring model, the nonrod separates two sub-nanorods and the flexibility of the axial spring represents the effect of the crack. Boundary ...

Structural vibration testing might be a promising method to study the mechanical properties of spinal motion segments as an alternative to imaging and spinal manipulation techniques. Structural vibration testing is a non-destructive measurement technique that measures the response of a system to an applied vibration as a function of frequency, and allows determination of modal parameters such a...