A hybrid longitudinal-torsional ultrasonic transducer is designed and fabricated in this research. The design of the transducer was performed using the FE method with ABAQUS software, with the aim of combining the longitudinal and torsional vibration modes. The transducer horn is then fabricated using a 4-axis milling machine. The PZT stacks are employed in order to excite the transducer. The t...

It has previously not been possible to measure eardrum vibration of human subjects in the region of auditory threshold. It is proposed that such measurements should provide information about the status of the mechanical amplifier in the cochlea. It is this amplifier that is responsible for our extraordinary hearing sensitivity. Here, we present results from a laser Doppler vibrometer that we de...

CRACK IDENTIFICATION ON A BEAM BY VIBRATION MEASUREMENT AND WAVELET ANALYSIS D.SRINIVASARAO, DR.K.MALLIKARJUNA RAO, DR.G.V.RAJU 1 Asst.Professor, Dept. of Mechanical Engineering, DMSSVH College of Engineering Machillipatnam, Krishna Dt. A.P., India 2 Professor, Dept. of Mechanical Engineering, JNTU, Kakinada, A.P., India 3 Professor, Dept. of Mechanical Engineering, SRKR Engineering College, Bh...

Osteocytes are well evidenced to be the major mechanosensor in bone, responsible for sending signals to the effector cells (osteoblasts and osteoclasts) that carry out bone formation and resorption. Consistent with this hypothesis, it has been shown that osteocytes release various soluble factors (e.g. transforming growth factor-beta, nitric oxide, and prostaglandins) that influence osteoblasti...

Abstract An upper limb motion assist robot to elderly and disabled people is proposed in this paper. The robot can be mounted on a wheelchair to actuate an elderly person’s upper limb three dimensionally by his will. A wrist of an arm is suspended, and actuated by a wire driven control system. A vibration reduction system is also developed to decrease the vibration occurred in the wire driven s...

Electromagnetic transducers have been used extensively for active feedback control of mechanical vibration. In this paper, we demonstrate a new technique where an electrical impedance, connected to the terminals of an electromagnetic actuator, is designed to reduce vibration in the host structure. By measuring the coil terminal voltage and controlling the resultant current or vice-versa the cou...

Mechanical vibration on mobile hard disk is inevitable in the practical usage, and violent vibration may cause disk slip with significant position error, which will degrade the servo control performance, prolong time to ready (TTR) of servo and lower reading and writing speed of the magnetic head. The servo tracking accuracy of hard disk drive actuator with respect to various mechanical disturb...

In the radio communications industry, one major problem is the vibration induced on to a frequency standard. The most commonly used frequency standard is the crystal oscillator; as the crystal oscillator gets vibrated with varying force and frequencies of vibration the phase noise of the signal changes. As the phase noise increases, the signal to noise ratio decreases causing the likelihood of ...

A hybrid longitudinal-torsional ultrasonic transducer is designed and fabricated in this research. The design of the transducer was performed using the FE method with ABAQUS software, with the aim of combining the longitudinal and torsional vibration modes. The transducer horn is then fabricated using a 4-axis milling machine. The PZT stacks are employed in order to excite the transducer. The t...

The goal of this study is investigating reduction of residual stresses from welding carbon steel plates through vibrationstress reliefmethod vs. thermal method. In order to carry out the required experimental tests, carbon steel plates were welded together under specific conditions as samples. Some of the samples were vibration stress relieved, some were thermal stress relieved while the rest r...