OBJECTIVE The aim of this study was to evaluate the effect of simulated periodontal ligament (SPDL) on custom cast dowel and core removal by ultrasonic vibration. MATERIAL AND METHODS Thirty-two human maxillary canines were included in resin cylinders with or without SPDL made from polyether impression material. In order to allow tensile testing, the roots included in resin cylinders with SPD...

In this research, the effect of vibration at the resonant range (75 Hz) on the hardness and tensile strength of AA-5083-H321 aluminum alloy, were welded by gas metal arc welding (GMAW) investigated. Vibration forces were ranged from 850 N to 2200 N, under identical welding parameters. Tensile strength and hardness testing of welded samples were performed. After mechanical tests, the fracture su...

In this research, the effect of vibration at the resonant range (75 Hz) on the hardness and tensile strength of AA-5083-H321 aluminum alloy, were welded by gas metal arc welding (GMAW) investigated. Vibration forces were ranged from 850 N to 2200 N, under identical welding parameters. Tensile strength and hardness testing of welded samples were performed. After mechanical tests, the fracture su...

Dynamic characteristics of a typical multistory building in Iran have been studied in two different stages of building construction, using ambient vibration tests. Finite element models have also been used to determine these characteristics and to verify test results. The results indicated the agreements and also differences between conventional theoretical models and the behaviour of real stru...

A new cogeneration installation was in the process of being commissioned when severe subsynchronous vibration was detected on the generator during no load tests. Subsequently, two rotordynamics problems were discovered. These problems prohibited the steam turbine generator set from reaching full speed. Additional vibration problems were anticipated once the generator was loaded and the steam fl...

The dynamic viscoelasticity of full-size wood composite panels (WCPs) under the free-free vibrational state were determined by a vibration testing method. Vibration detection tests were performed on 194 pieces of three types of full-size WCPs (particleboard, medium density fiberboard, and plywood (PW)). The dynamic viscoelasticity from smaller specimens cut from the panels was measured using a ...

THE FOURIER SPECTRAL ELEMENT METHOD FOR VIBRATION ANALYSIS OFGENERAL DYNAMIC STRUCTURESbyXUEFENG ZHANGMay 2012Advisor: Dr. Wen LiMajor: Mechanical EngineeringDegree: Doctor of PhilosophyThe Fourier Spectral Element Method (FSEM) was proposed by Wen Li on the vibrationof simple beams (Li, 2000), and was extended to the vibration of rectangular plates (Li, ...

This report contains the results of a full-scale experimental feasibility study of rotor isolation employing the Dynamic Antiresonant Vibration Isolator (DAVI) . The full-scale experiments were performed on a UH-2 helicopter fuselage isolated from a simulated rotor and transmission. Tests were conducted for three directions of vibratory input at the hub on the nonisolated vehicle and then compa...

In this paper the characteristics of the cold test technology will be described and a monitoring method for quality tests of diesel engines at the end of assembly line will be considered. A variety of different techniques for processing vibration signals has been proposed by many researchers but only a few applications in cold test monitoring exist. The determination of reliable threshold value...

In cooperation with the major propulsion engine manufacturers, the authors are developing and demonstrating a unique very high frequency (VHF) vibration monitoring system that integrates various vibroacoustic data with intelligent feature extraction and fault isolation algorithms to effectively assess engine gearbox and generator health. The system is capable of reporting on the early detection...