6926475970

Vibration model* for straight, conatent croM-*ectk>n, non-roteting cantłlever beam* are co nt id er ad with perttoular ragard for thote model* which include thaer deformation and rotary inert ia. A review of existing model* and article* baaring on improvements to these model* i* given. Three naw model* are introduced: a combined bending and torsion model for beam* of arbitrary crou-section which include* torsion war ping affects; a tymmetric bending model which include* bending werping effect*; and a tymmetric bending model which include* bending warping and anticlattic bending effect*.

84-1702

Coupled Flcxurai-ToraionaJ Yibration of Beam* in the Preeence of Static Axial Loads and End Moment*

A. Joshi and S. Suryanarayan

India Inst. of Tech., Bombay, India, J. Sound V»b.,

92 (4). pp 583-589 (Feb 22. 1984) 5 figs, 4 refs

Key Word*: Beam*, Co u pled retponae, Flexural vibratk>n, Torsion vbration

84-1704

The Reąsonse of a Beam to a Tran went Preaaure Wave Load

A. Kunow-Baumhauer

Mannesmann Anlagenbau AG, Theodorstrasse 90, 4000 Dusseldorf 30, W. Germany, J. Sound Vib., 92.(4), pp 491-506 (Feb 22. 1984) 9 figs, 3 tables. 9 refs

Key Word*: Beam*, Moving loads, Flexural waves, Wave propagation, Bernoulli-Euler method, Timothenko theory

The dynamie behavior of beam structures under preuure w*ves jj inve*tigated. The propagation of the bending wavet under a moving single load i* studied for three type* of beam: a Bernoulli-Euler beam, a beam wrth shear deflection and a Timothenko beam. The retpontet of the Bernoulli-Euler and the Timothenko beam are studied under moving preuure weve excitation. The retultt are pretented as dynamie amplification factors. The influence of the load parameter* (load ihape, propagation «>eed, preuure weve duration, etc.) and the beam parameter* (tlendernes*. damp-ing, etc.) itdiscutted.

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The problem of coupled flexural-torsional vbrat»n of a deep rectangular beam in the pretence of a static axiel load and an end moment i* studied. Closad form analytical Solutions are obtained for simply tupported boundary condi-tiont. Numerical retultt are obtained for the coupled fre-quencie* and moda shapet (in term* of the focatfen of axet of rotation of the crou-section) for different value* of the load and the geometry perameters.

84-1703

A Notę on the Acouatic Radiation from Point-Forced Elastic Beams

R.F. Keltie

North Carolina State Univ., Raleigh, NC 27650, J. Sound Vib., 22. (2). PP 253-260 (Jan 22. 1984) 3 figs, 9 refs

Key Word*: B«rs, Besms, Elestic properties, Demped structures, Sound waves, Wave radiation. Point source excitatk>n

An exact expreuion for the ecoustic power radiated by a point-excited damped bar i* derived through direct inttgra-tion of tha thaoretical surfaceacouStic intentity dittrlbution. Tha effect* of structural demping and wevenumbar ratio on tha power ara pretented 6xpre*«ion* are obtained for the contribution* to the total acoustic power erłsing from the propegating port ton of tha vibratory raaponse and tha non-propegating or flaxurai near fitld portton of tha vbra-tory reaponu. separataly.

84-1705

Influence of the Order of Polynomial on the Con-yergence in Ritz Finite Element Formula tion to Nonlinear Yibration* of Beam*

B.S. Sarma, G. Prathap. and T.K. Varadan Defence Res. and Dev. Lab.. Hyderabad. India, Com-puters Struć., 18.(4), pp 667-671 (1984) 3 tables. 6 refs

Key Word*: Beemt, Nonlineer vibretton. Finite element technique, Ritz method

The influence of the order of inplane polynomiel on the convergence of solution, when a Ritz finite element formu-lation i* used to study nonlineer vibratic s of beems. i* investigated. Three type* of polynomiel distrbutbns for the inplane disptecement u are oonsidered whila the polynomial dittribution tor trantvarsa di tpla cement w i* alwey* retainad as cubic. A hirtged-hingad beam on immovabla and* with diffarant discretization i* c ho ten as an exampłe for the convergence study on the nonlinear hardening parameter.

84-1706

Engineering Approxknatk>n of Beam Flutter

L.E. Ericsson

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