Bo Ping Wang

Vibration reduction over a frequency range

Abstract An efficient optimal design algorithm for minimizing the vibratory response of a multi-degree of freedom system under sinusoidal loading over several excitation frequencies is presented. The method is applicable to large scale dynamic systems because it incorporates an effective time-saving reanalysis approach to compute cost function and cost function derivatives. In particular, the efficiency of the method is demonstrated by applying it to the problem of designing two dynamic vibration absorbers simultaneously applied to an undamped cantilever beam.

Eigenvalue reanalysis of locally modified structures using a generalized Rayleigh's method

In this paper, we introduce approximate reanalysis methods based on the generalized Rayleighs quotient. With these methods, the fundamental eigenvalue of a locally modified system can be computed readily, using the fundamental mode as well as the static solution of the original system. Following a general development of theory, several special cases of in- terest in design are derived here and then tabulated. Numerical examples illustrate the accuracy of the new formulations.

Component Synthesis of Multi-Case, Rotating Machinery Trains by the Generalized Receptance Approach

A method is presented for computing the eigenvalues of multicase, coupled, rotating machinery trains. The method is based on a synthesis technique which utilizes generalized receptance formulas, previously derived by the authors. These formulas improve the accuracy of the computed receptances when only an incomplete set of modes is available. A nonsynchronous, gyroscopic, two rotor example is examined to illustrate the synthesis procedure.Copyright

Limiting performance of ground transportation vehicles subject to transient loading

For numerous instances in the study of the dynamics of ground transportation systems it is valuable to know the true optimal performance. That is, the limiting performance is desired regardless of the design configuration of those portions of the system under consideration, e.g., suspension systems. A computational approach for determining this limiting performance of vehicles subject to transient disturbances based on response variable criteria is set forth in this Synoptic. For the purpose of a limiting performance study, the transportation system dynamics are described using the second- or first-order equations = F/ k

Structural Reanalysis Revisited

Both exact and approximate reanalysis are viewed as a form of Ritz analysis. These formulations are applicable to static, steady state and free vibration reanalysis problems

The frontal transfer matrix method. Efficient solution of transfer matrix and reanalysis.

伝達マトリックス法は,特に直線状の構造物解析には,きわめて有効な構造解析法である.しかし伝達マトリックスの数値計算で,解が不安定になったり誤差が増加してしまうことがある.本論文では有限要素法などで使われるフロンタル解法を応用し,部分マトリックスの逐次リダクションによって計算の安定化と効率化をはかる方法を提案する.この計算方法は部分構造の特性変化を評価するリアナリシスへも,効率よく適用可能である.

Eigensolution Reanalysis of Rotor Dynamic Systems by the Generalized Receptance Method

A method is presented for efficiently calculating the damped natural frequencies of complex rotor bearings systems. The procedure is applicable to the repeated reanalysis of rotor systems during the search for an optimal design. The generalized receptances used in the method are calculated with a series of formulas that improves the convergence characteristics when only an incomplete set of modes is available. A nonsynchronous gyroscopic rotor example is examined to illustrate the reanalysis procedure.Copyright