A Study on a Vibratory Model of a Human Body

1987 ◽  
Vol 109 (2) ◽  
pp. 148-153 ◽  
Author(s):  
S. P. Nigam ◽  
M. Malik
Keyword(s):  
Human Body ◽  
Natural Frequencies ◽  
Degree Of Freedom ◽  
Male Body ◽  
Mass System ◽  
Modeling Procedure ◽  
Experimental Values

This paper is concerned with the modeling of the human body as a spring mass system. Based on certain assumptions, an analysis for evaluating the mass and stiffness values of the model is developed. As an illustration of the modeling procedure, a 15-degree-of-freedom model of a male body is considered. The computed natural frequencies of the model are found to be within the range of available experimental values.

Determination of the first n modes of a tall building from a reduced eigenvalue problem

1964 ◽  
Vol 54 (4) ◽  
pp. 1233-1254
Author(s):  
Moshe F. Rubinstein
Keyword(s):  
Eigenvalue Problem ◽  
Natural Frequencies ◽  
Tall Building ◽  
Degree Of Freedom ◽  
Mode Shapes ◽  
Story Building

Abstract The first n natural frequencies and mode shapes of an N degree of freedom structure (n < N) are derived from the solution of a reduced eigenvalue problem of order smaller than N. The reduced eigenvalue problem is formulated by using experience to select approximations to the first n modes desired. Accuracy is improved when more than n modes are selected. The method is illustrated by a study on an 18 story building.

Teaching to draw a nude male body from the front with a pencil drawing

2021 ◽  
Vol 2 (3/S) ◽  
pp. 361-365
Author(s):  
Chori Sadatov
Keyword(s):  
Human Body ◽  
Male Body ◽  
Topical Issue ◽  
Methodological Basis ◽  
Pencil Drawing

At present, research is underway to develop a theoretical and methodological basis for teaching the science of calligraphy, a new scientifically based way, form, content and methods, and it is a topical issue.  The process of drawing a human body is done step by step.  Of course, academic drawing operations are used.  It is revealed through the transition from simple to complex.

Free and Forced Wave Vibration Analysis of a Timoshenko Beam/Frame Carrying a Two-Degree-of-Freedom Spring-Mass System

2021 ◽  
pp. 1-25
Author(s):  
Carole Mei
Keyword(s):  
Timoshenko Beam ◽  
Discrete Systems ◽  
Degree Of Freedom ◽  
Combined System ◽  
Bending Vibrations ◽  
Mass System ◽  
Short Beam ◽  
Beam Frame ◽  
Classical Vibration ◽  
Two Degree Of Freedom

Abstract In this paper, free and forced vibrations of a transversely vibrating Timoshenko beam/frame carrying a discrete two-degree-of-freedom spring-mass system are analyzed using the wave vibration approach, in which vibrations are described as waves that propagate along uniform structural elements and are reflected and transmitted at structural discontinuities. From the wave vibration standpoint, external excitations applied to a structure have the effect of injecting vibration waves to the structure. In the combined beam/frame and two-degree-of-freedom spring-mass system, the vibrating discrete spring-mass system injects waves into the distributed beam/frame through the spring forces at the two spring attached points. Assembling the propagation, reflection, transmission, and external force injected wave relations in the beam/frame provides an analytical solution to vibrations of the combined system. In this study, the effects of rotary inertia and shear deformation on bending vibrations are taken into account, which is important when the combined structure involves short beam element or when higher frequency modes are of interest. Numerical examples are given, with comparisons to available results based on classical vibration theories. The wave vibration approach is seen to provide a systematic and concise solution to both free and forced vibration problems in hybrid distributed and discrete systems.

The Use of Rubber in Vibration Isolation: Including the Case of Six Degree of Freedom Systems

1937 ◽  
Vol 4 (3) ◽  
pp. A109-A114
Author(s):  
E. H. Hull
Keyword(s):  
Elastic Properties ◽  
Elastic Material ◽  
Vibration Isolation ◽  
Natural Frequencies ◽  
Degree Of Freedom ◽  
Modes Of Vibration ◽  
Six Degree Of Freedom

Abstract The desirable properties of an elastic material applicable to many types of vibration-isolation problems are outlined. Of those materials at present available, rubber appears most suitable for this type of work. The general elastic properties of rubber are discussed and data given for determining the stiffness of pads made from one particular compound. Equations are developed for the six natural frequencies and associated modes of vibration of a mass supported on elastic pads and examples of vibration isolation worked out using this theory.

Prediction and analysis of compression behaviour of warp-knitted spacer fabric with cylindrical surface

2018 ◽  
Vol 48 (9) ◽  
pp. 1489-1504 ◽  
Author(s):  
Mrinal K Datta ◽  
B K Behera ◽  
Ashvani Goyal
Keyword(s):  
Human Body ◽  
Cylindrical Surface ◽  
Radius Of Curvature ◽  
Body Parts ◽  
Energy Effect ◽  
Compression Behaviour ◽  
Spacer Fabric ◽  
Medical Textile ◽  
Experimental Values ◽  
Spacer Fabrics

Nowadays, applications of spacer fabric cover wider areas of technical textile. It is used in the automotive textile, personal protective clothing, sports textile, foundation garments, pads for swimwear, buffer clothing, medical textile etc. It does possess good recovery to compression, high bulk with relatively lightweight and very good moisture permeability. Almost in all applications, spacer fabrics are compressed by different parts of human body. Body parts have different shapes and curvatures. In all standard methods, spacer fabric compressibility is measured by a pair of flat circular plate which cannot represent a human body. The contour of body can be assumed as cylindrical with varying radius of curvature. So, it is necessary to understand the mechanism of compression of spacer fabric with cylindrical surface in order to understand the performance of the fabric under real-world dynamics. In this research, an effort is being made to predict the compression behaviour of warp-knitted spacer fabric by flat as well as cylindrical surface. Finite Element Models were designed on Abaqus/CAE platform to meet above requirement with variable circumstances. Experimental setup was also made to analyse cylindrical and flat compression at different circumstances. Results show that flat compression and cylindrical compression are largely deferred in terms of shape of load-deformation curve and compressional energy. Effect of variables on compression behaviour was also analysed. Model results were validated with experimental values. It is found that the proposed model has got a good agreement with the experimental results.

Nonlinear Vibrations of a Beam-Spring-Large Mass System

2017 ◽  
Author(s):  
Mohammad A. Bukhari ◽  
Oumar R. Barry
Keyword(s):  
Natural Frequencies ◽  
Multiple Scales ◽  
Equations Of Motion ◽  
Primary Resonance ◽  
Large Mass ◽  
Mode Shapes ◽  
Resonance Excitation ◽  
Response Curves ◽  
Mass System ◽  
Spring System

This paper presents the nonlinear vibration of a simply supported Euler-Bernoulli beam with a mass-spring system subjected to a primary resonance excitation. The nonlinearity is due to the mid-plane stretching and cubic spring stiffness. The equations of motion and the boundary conditions are derived using Hamiltons principle. The nonlinear system of equations are solved using the method of multiple scales. Explicit expressions are obtained for the mode shapes, natural frequencies, nonlinear frequencies, and frequency response curves. The validity of the results is demonstrated via comparison with results in the literature. Exact natural frequencies are obtained for different locations, rotational inertias, and masses.

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