Title

Analytical And Experimental Modal Analysis Of A Two-Tiered Structure

Report Number

WL-TR-91-3078 Volume I, p. DAB-1 thru DAB-11

Creator

Vu, H. V.

Vuong, T. K.

Flynn, Jr., W. C.

Corporate Author

Department of Mechanical Engineering,California State University, Long Beach

Laboratory

Wright Laboratory

Date

1991

Date Issued

1991-08

Extent

11

Contract

Laboratory Research - No Contract

DoD Project

2401

DoD Task

240104

Identifier

ADA241311

Format

1 online resource

Abstract

A test structure, namely a two-tiered structure (TIS), was used as a physical model for obtaining modal parameters of flexible structures. These parameters, which were determined analytically and experimentally, are natural frequencies, mode shapes, and damping ratios. In the analytical portion, finite element method (FEM) was used with MSC/NASTRAN, MSC/pal 2, and MSC/MOD. In the experimental part, the structure was excited by random noise, and frequency-response function (FRF) plot and modal parameters were obtained. Both the HP 3566N3567 A (Hewlett Packard Spectrum/Network Analyzer) and STAR System (Structural Measurement Systems software) were utilized. An exact model-reduction technique was used to obtain a complete mathematical model of a reduced-order system, which includes the reduced-order physical mass, stiffness, and damping matrices.

Description

A test structure, namely a two-tiered structure (TIS), was used as a physical model for obtaining modal parameters of flexible structures. These parameters, which were determined analytically and experimentally, are natural frequencies, mode shapes, and damping ratios. In the analytical portion, finite element method (FEM) was used with MSC/NASTRAN, MSC/pal 2, and MSC/MOD. In the experimental part, the structure was excited by random noise, and frequency-response function (FRF) plot and modal parameters were obtained. Both the HP 3566N3567 A (Hewlett Packard Spectrum/Network Analyzer) and STAR System (Structural Measurement Systems software) were utilized. An exact model-reduction technique was used to obtain a complete mathematical model of a reduced-order system, which includes the reduced-order physical mass, stiffness, and damping matrices.

Distribution Classification

1

Distribution Conflict

No

DTIC Record Exists

No

Illinois Tech Related

No

Photo Quality

Not Needed

Report Availability

Full text available

Type

article

Is Part Of

Proceedings of Damping '91: 13-15 February 1991 San Diego, California (Pages AAC-1 through DCC-19)