An Experimental Verification of the Hemispherical Cup Puckering Problem

1989 ◽  
Vol 111 (3) ◽  
pp. 248-254 ◽  
Author(s):  
M. Donoghue ◽  
R. Stevenson ◽  
Y. J. Kwon ◽  
N. Triantafyllidis
Keyword(s):  
Experimental Study ◽  
Numerical Solution ◽  
Analytical Model ◽  
Experimental Verification ◽  
Critical Discussion ◽  
Solution Technique ◽  
Practical Reasons ◽  
Experimental Procedure ◽  
Theoretical Results

In this work is presented an experimental study of the hemispherical cup puckering test. This investigation is motivated by some theoretical as well as by some practical reasons which are elaborated upon in the introduction. After a brief outline of the analytical model and the corresponding numerical solution technique, the presentation continues with a description of the experimental procedure. A comparison between the experimental and the theoretical results is given next followed by a critical discussion.

Experimental Verification of the Importance of The Nonlinear Curvature in the Response of a Cantilever Beam

1996 ◽  
Vol 118 (1) ◽  
pp. 21-27 ◽  
Author(s):  
T. J. Anderson ◽  
A. H. Nayfeh ◽  
B. Balachandran
Keyword(s):  
Analytical Model ◽  
Cantilever Beam ◽  
Theoretical Investigation ◽  
Experimental Verification ◽  
Dominant Role ◽  
Experimental Results ◽  
Parametrically Excited ◽  
Second Mode ◽  
Quadratic Damping ◽  
Theoretical Results

An experimental and theoretical investigation into the first- and second-mode responses of a parametrically excited slender cantilever beam is presented. Inclusion of quadratic damping in the analytical model significantly improves the agreement between the experimental and theoretical results. In addition, the experimental results verify that the often ignored nonlinear curvature terms play a dominant role in the response of the first mode and that the nonlinear inertia terms play a dominant role in the response of the second mode.

Analytical and Experimental Study on Balancing Using Influence Coefficient Method

2013 ◽  
Vol 393 ◽  
pp. 694-702
Author(s):  
Wan Sulaiman Wan Mohamad ◽  
A.A. Mat Isa ◽  
M.A. Ismail
Keyword(s):  
Experimental Study ◽  
Experimental Verification ◽  
Mass Concentration ◽  
Vibration Reduction ◽  
Influence Coefficient ◽  
Centrifugal Forces ◽  
Experimental Procedure ◽  
Influence Coefficient Method ◽  
Phase Angles ◽  
Coefficient Method

Unbalance effect on rotating element happens as a result of an off centered mass concentration which will generate centrifugal forces with increasing running speeds. This unwanted situation requires correction to avoid failure due to excessive vibration. In this study, unbalance problem are studied by using theoretical influence coefficient method followed by the experimental verification. Experimental procedure is performed by using trial mass to calculate the influence coefficient and the corrected mass values as well as the phase angles. Finally, the vibration reduction of the rotor is compared theoretically and experimentally. Based on the results, the improved vibration reduction could be obtained reasonably for both single and two-plane balancing by using influence coefficient method.

The accurate measurement of permittivity by means of an open resonator

1971 ◽  
Vol 325 (1563) ◽  
pp. 493-509 ◽  
Keyword(s):  
Experimental Study ◽  
Present Method ◽  
Open Resonator ◽  
Experimental Procedure ◽  
Microwave Frequencies ◽  
Experimental Errors

A method for the measurement of permittivity at microwave frequencies using an open resonator is proposed. The theory of the method is developed, and an experimental procedure is evolved and justified. It is shown that the present method has advantages over other open resonator methods which have been proposed, and a thorough experimental study of the method has shown that experimental errors can be made very small indeed.

Experimental Study on the Failure Criterion for Brittle Materials in Compression

2011 ◽  
Vol 320 ◽  
pp. 259-262
Author(s):  
Xu Ran ◽  
Zhe Ming Zhu ◽  
Hao Tang
Keyword(s):  
Thin Film ◽  
Experimental Study ◽  
Compressive Strength ◽  
Fracture Mechanics ◽  
Failure Criterion ◽  
Brittle Materials ◽  
Experimental Results ◽  
Experiment Study ◽  
Confining Stress ◽  
Theoretical Results

The mechanical behavior of multi-cracks under compression has become a very important project in the field of fracture mechanics and rock mechanics. In this paper, based on the previous theoretical results of the failure criterion for brittle materials under compression, experiment study is implemented. The specimens are square plates and are made of cement, sand and water, and the cracks are made by using a very thin film (0.1 mm). The relations of material compressive strength versus crack spacing and the lateral confining stress are obtained from experimental results. The experimental results agree well with the failure criterion for brittle materials under compression, which indicates that the criterion is effective and applicable.

Study of the Effect of Hole Clearance and Thread Fit on the Self-Loosening of Threaded Fasteners

2006 ◽  
Vol 129 (6) ◽  
pp. 586-594 ◽  
Author(s):  
Sayed A. Nassar ◽  
Basil A. Housari
Keyword(s):  
Analytical Investigation ◽  
The Self ◽  
Time Data ◽  
Experimental Procedure ◽  
Test Setup ◽  
Threaded Fasteners ◽  
Service Load ◽  
Real Time Data ◽  
Theoretical Results ◽  
Simplified Mathematical Model

This study provides an experimental and theoretical investigation of the effect of hole clearance and thread fit on the self-loosening of tightened threaded fasteners that are subjected to a cyclic transverse service load. An experimental procedure and test setup are developed in order to collect real-time data on the rate of clamp load loss per cycle as well as the loosening rotation of the bolt head. Three levels of hole clearance are investigated; namely, 3%, 6%, and 10% of the bolt nominal diameter. For the commonly used 2A thread fit for a selected bolt size, three classes of the nut thread fit are considered; namely, 1B, 2B, and 3B. A simplified mathematical model is used for the analytical investigation of the effect of the hole clearance and thread fit on threaded fasteners self-loosening. The experimental and theoretical results are presented and discussed.

Theory and Measurements of the Propeller-Induced Vibratory Pressure Field

1972 ◽  
Vol 16 (02) ◽  
pp. 124-139
Author(s):  
W. R. Jacobs ◽  
J. Mercier ◽  
S. Tsakonas
Keyword(s):  
High Speed ◽  
Pressure Field ◽  
Processing Technique ◽  
Experimental Program ◽  
Signal Processing Technique ◽  
Experimental Procedure ◽  
Surface Theory ◽  
Blade Frequency ◽  
Development Center ◽  
Theoretical Results

A theory has been developed, based on lifting surface theory, for evaluation of the pressure field generated by an operating propeller in a nonuniform inflow field. In addition, an experimental procedure and a signal processing technique for measuring small pressure levels accurately have been established and utilized in an extensive experimental program. Theoretical results obtained by means of a computer program developed for the CDC 6600 high-speed digital computer agree well with those of experiments conducted at Davidson Laboratory and at the Naval Ship Research and Development Center. The difficulty of accurately establishing by measurements the decay of small pressures at points farther than one radius from the propeller precludes the possibility of determining the blade-frequency force exerted on a flat boundary by integrating the measured signatures. In contrast, integration of double the theoretical free-space pressure over the flat boundary appears to be a feasible and meaningful approach.

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