MODELLING OF NON-LINEAR OSCILLATIONS OF ELASTIC STRUCTURES IN HEAVY FLUID LOADING CONDITIONS

1999 ◽  
Vol 222 (3) ◽  
pp. 425-451 ◽  
Author(s):  
S.V. Sorokin ◽  
S.G. Kadyrov
Keyword(s):  
Loading Conditions ◽  
Fluid Loading ◽  
Heavy Fluid ◽  
Elastic Structures ◽  
Non Linear

The modes, resonances and forced response of elastic structures under heavy fluid loading

1984 ◽  
Vol 312 (1521) ◽  
pp. 295-341 ◽  
Keyword(s):  
Order Approximation ◽  
Low Frequency ◽  
Forced Response ◽  
Mode Shapes ◽  
Thin Elastic Plate ◽  
Fluid Loading ◽  
Heavy Fluid ◽  
Elastic Structures ◽  
Strip Plate ◽  
First Time

This paper reports analytical studies of problems that involve the motion of plane elastic structures under conditions of heavy fluid loading. The main aspect concerns the description of the vibration response of a thin elastic plate (or membrane), of finite extent in at least one dimension, when the structure is excited by concentrated mechanical drive along a line or at a point; and as part of this the possibility of resonant response is discussed, and the resonance conditions and free modes of oscillation are obtained. There is also some discussion of the acoustic fields radiated by the structures under localized mechanical excitation. The analysis makes extensive use of results for the reflection of a structural wave (subject to heavy fluid loading) at an edge, and the paper gives results for that reflection process covering waves incident normally on eight different edge configurations and waves incident obliquely on two edge configurations. These results include the reflection coefficient (whose magnitude is unity in the leading-order approximation of low-frequency heavy fluid loading), and the amplitude and directivity of the edge-scattered sound. By using the argument that edge reflection is a local process, the response is then calculated for a strip plate, under both line and point forcing, and the response is, for the first time, obtained for structures finite in both dimensions and subject to heavy fluid loading. Specifically, solutions are given here for a circular plate with eccentric drive, and for a membrane model of a rectangular panel, with central point drive. For some conditions and geometries expressions in simple form are found for the natural frequencies and mode shapes, and for the off-resonance forced response. Expressions for the drive admittances are found which display a variety of interesting features.

An Automated Implementation of a Cantilever Calibration Technique for Heavy Fluid Loading Environments

2009 ◽  
Author(s):  
Scott J. Kennedy ◽  
Daniel G. Cole ◽  
Robert L. Clark
Keyword(s):  
Atomic Force Microscopy ◽  
Original Description ◽  
Loading Conditions ◽  
Fluid Loading ◽  
Heavy Fluid ◽  
Calibration Technique ◽  
Force Microscopy ◽  
Atomic Force ◽  
Matlab Program ◽  
Force Calibration

In a recently submitted paper, a technique is presented for the force calibration of atomic force microscopy (AFM) cantilevers under heavy fluid loading conditions, such as those commonly found in liquid environments. A Matlab program had been made available that automates this technique. In this paper, the analysis performed by this program is explained with specific attention to the details that do not appear in the original description of the calibration technique, but arise in the automated implementation.

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