Large machine and structure can not be normally treated as lumped parameter system. Such machine or structure must be broken down to individual beams or panels the motion of which must be analysed before an absorber system can be designed for each element. The absorber may be a lumped parameter system or a continuous system. One of the most common elements in a machine or structure is the cantilever, and in this paper is considered the design of a continuous parameter absorber to reduce the transverse vibrations of a beam. So this paper describes the method to obtain the accurate information about combined continuous beam system with DVA. This information is obtained from the combined system's receptance. and this paper shows the convenience and useful informations when design the dynamic vibration absorber with the combined system's receptance.

In this paper, the torque of CNC spindle motor during machining is estimated without speed measuring sensor. The CNC spindle system is divided into two parts, the induction spindle motor part and mechanical part. In mechanical part, the variation of the frictional force due to the increment of the cutting torque and the effect of damping coefficient is investigated. Damping coefficient is found to be a function of spindle speed and not influenced by the weight of the load, while frictional force is a function of both the cutting torque and spindle speed. Experimental equations are drawn for damping coefficient and Coulomb friction as a function of spindle speed. Incremental frictional torque Is also obtained as a function of both cutting torque and spindle speed. Graphical programming is used to implement the suggested algorithm to monitor the torque of an induction motor in real time. Torque of the spindle induction motor is estimated well in about average 3% error range under various cutting conditions.

Lane Sensing techniques based on vision sensors are regarded promising because they require little infrastructure on the highway except clear lane markers. However, they require more intelligent processing algorithms in vehicles to generate the previewed roadway from the vision images. In this paper, a lane sensing algorithm using vision sensors is developed to improve the sensing robustness. The parallel stereo-camera is utilized to regenerate the 3-dimensional road geometry. The lane geometry models are derived such that their parameters represent the road curvature, lateral offset and heading angle, respectively. The parameters of the lane geometry models are estimated by the Kalman filter and utilized to reconstruct the lane geometry in the global coordinate. The inverse perspective mapping from the image plane to the global coordinate considers roll and pitch motions of a vehicle so that the mapping error is minimized during acceleration, braking or steering. The proposed sensing system has been built and implemented on a 1/10-scale model car.

To monitor the torque of an induction motor using current, the accurate identification of the motor parameters is very important. In this study, the motor parameters such as rotor resistance, stator and rotor leakage inductance, mutual inductance are estimated for torque monitoring and indirect vector control. Estimated parameters are used to monitor the torque of vector controlled induction motor without any speed measuring sensor. Stator current is measured to estimate the magnetizing current which is used to calculate flux linkage, rotor velocity and motor torque. From the experiments, the proposed method shows a good estimation of the motor parameters and torque under the normal rotational speed.

This paper proposes a new method of measuring an air interface distance between a solid immersion lens(SIL) applied magneto-optic technology and the disk surface. For applying near-field recording (NFR) technology to the magneto-optic storage devices for the next generation, it is positively necessary to maintain the small air gap under about 100㎚. We design an apparatus that consists of some optical components such as a prism, a polarizer and an analyzer. By using the Fresnel reflection coefficient equation, Jones matrices calculation and Malus's law, we establish a mathematical model for understanding the characteristics of the system. The simulations are based on the mathematical model and through the simulation results which is made with various cases we can estimate the performance of the new optical gap sensor system. Experimental results, which are also based on the mathematical model for specific cases, are in good agreement with simulated ones and demonstrate the possibility as the new optical gap sensor.

Since the multiscale wavelet-based numerical methods allow effective adaptive analysis, they have become new analysis tools. However, the main applications of these methods have been mainly on elliptic problems, they are rarely used for eigenvalue analysis. The objective of this paper is to develop a new multiscale wavelet-based adaptive Galerkin method for eigenvalue analysis. To this end, we employ the hat interpolation wavelets as the basis functions of the finite-dimensional trial function space and formulate a multiresolution analysis approach using the multiscale wavelet-Galerkin method. It is then shown that this multiresolution formulation makes iterative eigensolvers very efficient. The intrinsic difference-checking nature of wavelets is shown to play a critical role in the adaptive analysis. The effectiveness of the present approach will be examined in terms of the total numbers of required nodes and CPU times.

Detailed two-dimensional and three-dimensional finite element (FE) analyses of double-edge cracked tension (DE(T)) specimens are carried out to investigate the effect of the relative crack length and the thickness on experimental J testing schemes. Finite element analyses involve systematic variations of relevant parameters, such as the relative crack depth and plate width-to-thickness ratio. Furthermore, the strain hardening index of material is systematically varied, including perfectly plastic (non-hardening) cases. Based on FE results, a robust experimental J estimation scheme is proposed.

The purpose of this paper is to develop a systematic design method for the suspension system hard points and compliance elements, which have great influence on the handling stability of a vehicle. In this paper, a method to optimize J-turn responses is presented based on the principles of design of experiments, multi-body dynamic analysis and optimum design technique. The design variables associated with the J-turn maneuver are selected through the experimental design sensitivity analysis using the perturbation method. An objective function is defined as an approximate function for the J-turn characteristics using the TSA(Taylor series approximation). The values of the design variables, which make the optimized J-turn characteristics, are obtained using the conjugate gradient method. The result of the J-turn simulation shows that the optimized vehicle has more improved handling stability than the optimized vehicle.

This paper presents the analysis fur the radial vibration characteristics of cylindrical piezoelectric transducers. Taking into account the piezoelectric anisotropy, the differential equations of piezoelectric radial motion have been derived in terms of radial displacement and electric potential. Applying mechanical and electric boundary conditions has yielded a characteristic equation for radial vibration. Numerical analysis also has been carried out by using the finite element method. Theoretical calculations of the fundamental natural frequency have been compared with the experimental observations for transducers of several sizes. Comparison with the previous report of theoretical analysis simplifying the piezoelectric anisotropy into isotropy concludes that isotropic analysis is a reasonable process to predict the vibration characteristics of piezoelectric transducers.

The hybrid composite material (Al/GFRP laminates) are applied to the fuselage and wing in a aircraft. Therefore, Al/GFRP laminates suffer from the cyclic bending moments. This study was to evaluate the effect of fiber stacking angle on the fatigue crack propagation and delamination behavior using the relationship between crack growth rate (da/dN) and stress intensity factor range (ΔK) in Al/GFRP laminates under cyclic bending moment. The variable delamination growth behavior in case of three different type of fiber orientations, i.e., [Al/O$_2$/Al], [Al/+45$_2$/Al] and [Al/90$_2$/Al] at the interface of Al layer and glass fiber layer was measured by ultrasonic C-scan images. As results of this study, It represent that the delamination shape should turns out to have more effective characteristics on the fiber stacking angle. The extension of the delamination zone in case of [Al/+45$_2$/Al] and [Al/90$_2$/Al] were not formed along the fatigue crack profile. The shape of delamination zone depend on fiber stacking angle and the variable type with the delamination contour decreased non-linearly toward the crack tip at the Al layer.

Pressure tubes are major component of nuclear reactor, but only selected samples are periodically examined due to numerous numbers of tubes. Current in-service inspection result show there is high probability of flaw existence at uninspected pressure tube. Probabilistic analysis is applied in this study for the integrity assessment of uninspected pressure tube. All the current integrity evaluations procedures are based on conventional deterministic approaches. So it is expected that the results obtained are too conservative to perform a rational evaluation of lifetime. More realistic failure criteria, based on FAD are also proposed for the probabilistic analysis. As a result of this study failure probabilities for various conditions are calculated, and examined application of FAD and LBB concept.

Recently, the ultra light metal structure with periodic and three dimensional truss elements takes attention because of its multi-functionality and substantial heat resistance. However, the complicated fabrication process leading to high cost has been a major obstacle to wide applications. In this paper, a new idea to construct an ultra light structure with periodic, three dimensional truss using metal wires is presented. To prove the practical validity, a Kagome-like structure was fabricated from stamped wires and punched face sheets. It was assembled by soldering. Through three-point bending and compression tests, the strength was evaluated and compared with the theory.

In this paper, cracking threshold for nanoindentation is analyzed by using 3D finited-element method. The analysis by maximum principal stress criterion can obtain the reliable results for determining to crack initiation location and load. Because the ratio of maximum principal stress to indentation depth for Victors indentation is smaller than flat-plane-column indentation and cracking for Victors indentation occurs from the inner part of specimen difficult to measure crack length, the nanoindentation facture test for flat-plane-column indentation is more effective.

This paper proposes engineering estimation equations for the maximum deflection of a cylinder subject to bending under elastic-plastic and elastic-creep conditions. Being based on the reference stress approach, the proposed equations are simple to use and can accommodate general tensile and creep behaviours. Validation against detailed 3-D FE results using actual stress-strain data and realistic creep-deformation data shows excellent agreement, which provides confidence in the use of the proposed equation. Based on the proposed equations, together with information on in-service inspection data, discussion is given how to estimate future time-dependent and time-independent deflection of the CANDU pressure tube. Thus the present result would be valuable information for integrity assessment of the CANDU pressure tube.

The stability of a simply supported straight pipe is investigated. The time dependent flow is assumed to vary harmonically about a constant mean velocity. Stability conditions and dynamic reponses of a governing equation are conducted by use of multiple scale mettled. Parametric resonances and combination resonances are investigated. Stability boundaries are analytically determined. The resulted stability conditions show that instabilities exist when the frequency of flow fluctuation is close to two times the natural frequency or to the sum of any two natural frequencies. In case that the fluctuated flow frequency is close to zero or to the difference of two natural frequencies, however, instabilities are not found up to the first order of perturbation. Stability charts are numerically Presented fir the first two vibration modes.