A numerical simulation method by the transfer matrix method is prorosed to compute the vibratiom stress wavef orms of a V-type, 8 cylinder Diesel engine crankshaft in this work. This method will be able to predict the conditions of vibration stresses and be useful to design a crankshaft.
The accuracy of this numerical method is considered by comparing the reuslts of the computation with the measured data. As a result of the comparisons with the measured data, it has been assured that the vibration stress wavef orms can be computed with adequate accuracy by considering from 0.5th to 10th or 12th order per 0.5th order harmonic components of exciting forces for a 4 cycele engine.

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To attain the quietness of vehicle such as automotobiles, ships and airplans, which are mostly composed of plate elements, the reduction of structure-borne noise is important, and for which the damping treatment by using viscoelastic materials is effective.
In adoption of this treatemnt, difficult problems are the systematic design of damped structures and the prediction of damping effects, taking the damping material properties into accont.
This paper presents a predeiction method of vibration reduction by damping teratment applied viscoelastic materials.
The major points of this paper are as follows.
1) To determine the vibratory characteristiscs of damped beams, an iterative desing procedure, taking the temperature and the frequency dependence of damping material properties is taken into acount, is shown.
2) To estimte the vibration reduction by damping teratments, two methods based on both the modal analysis and the SEA method are shown. The former is for the stiffer structures which are characterized with lowmodal density as engine structure, and the latter is for structures of high-modal density.
And the estimated results using these methods are well agreed with the measured ones.

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There are many machines having rotating parts such as blower, compressor including steam turbine and gas turbine. The moving blades, in particular, among rotating parts are the major element which has an influence upon the product reliability. The purposes of measuring the blade vibration are classified into the f ollowig three categories.
The first purpose is the quality evaluation of the products, and it is confirmed by a vibration test that the prototype, the actual machine, etc. have the same vibration characteristics as they are designed. The second purpose is the investigation for studying the phenomenon of blade vibration and its causes. Particularly, the information which is obtained from the vibration measurement plays an important role in solving the problems in vibration. The third purpose is the monitor of vibration and diagnosis of abnormality needs of which are recently increasing. This purpose is positioned intermediately between the above purposes. When the vibration is measured for any purpose, it is required that blade frequency, vibration mode and vibration response as well as exciting force and damping. However, in order to execute the vibration test meeting the purpose, it is important that not only the vibraton phenomenon but also the procedure for measurement are fully understood and the appropriate measuring methods are selected.
On the other hand when the blade vibraton tests are classified from the viewpoint of measuring method, they are roughly divided into the blade vibration tests under stationary condition and under rotating condition. The blade vibration test under stationary condition is fundamentally same as the vibraton test of general structures, however in the blade vibration test under rotating condition the technology and procedures peculiar to the vibration measurement of the rotors are required for all of measuring sensor, wiring method, transmission method of signals, and analysis method of data. In consideration of these matters, the recent tendency for the measuring method of vibration of high speed turbine blades is described in this paper.

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To estimate the gear mating conditions by processing the vibration signals, tried to use the Hilbert transformation method. The gear vibration signals were generated by the gear simulator which simulate a pair of mating spur gear vibration with teeth error using digital computer, then the simulated time discrete data were analyzed with same computer.
In conclusion, the Hilbert transformation method is useful for recognizing the gear mating conditions, especially for pattern comparison using the figure projected to complex plane. And also, it is able to estimate the gear teeth error quantitatively by analizing the phase information, but for the case of large teeth error it may cause extreme phase error.

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