Effect of Workpart Curvature on the Stiffness Properties of Circular Filamentary Brushes

1991 ◽  
Vol 113 (3) ◽  
pp. 276-282 ◽  
Author(s):  
S. M. Heinrich ◽  
R. J. Stango ◽  
Chih Yuan Shia

In this paper the role which workpart geometry plays in the stiffness properties and contact zone characteristics of circular filamentary brushes is investigated. The problem is examined by employing a recently developed mechanics-based procedure for evaluating large filament deformation, in conjunction with appropriate kinematic constraints for filament tip contact with a smooth, rigid workpart of prescribed constant curvature. Numerical examples for a circular filamentary brush system are presented and discussed for the purpose of illustrating the basic nature of brush stiffness response characteristics for a range of prescribed constant-curvature workpart surfaces.

1989 ◽  
Vol 111 (3) ◽  
pp. 238-243 ◽  
Author(s):  
R. J. Stango ◽  
S. M. Heinrich ◽  
C. Y. Shia

In this paper, an analytical procedure is developed for evaluating the filament loading, constrained elastic deformation, and overall stiffness of a circular brush, Filament deformation is computed on the basis of a large displacement mechanics analysis in conjunction with kinematic constraints for a flat, rigid workpart with smooth surface finish. Numerical results are reported which examine the relationship between workpart penetration, brush stiffness, and force distribution characteristics of the workpart contact zone.


Author(s):  
R. S. Hwang ◽  
E. J. Haug

Abstract Formulations of translational kinematic constraints between flexible bodies are developed to model deformatioin of flexible surfaces that move relative to one another. Three types of flexible translational articulated joints are presented The joint formulations are illustrated in analysis of prototype systems with translational joints. Global deformation modes and substructure local deformation modes are used and compared in numerical examples.


2011 ◽  
Vol 3 (3) ◽  
pp. 105-111 ◽  
Author(s):  
Robertas Zavalis ◽  
Bronius Jonaitis

In this paper, the analysis of various effects that have influence to the mechanical properties of masonry is made. Masonry is nonhomogeneous and anisotropic material composed of two materials with different stiffness properties. In order to analyze masonry deformations it is necessary to evaluate all effects that have influence to masonry mechanical properties (Table 1). The analysis of stress-strain state of masonry is presented in this paper. During the analysis of stressstrain state, the mechanical properties of masonry units and mortar were defined from experimental investigation of samples of unit and mortar materials. The following conclusions were reached based on the analysis of experimental data: 1) The deformations and stresses along the height of masonry unit distributes unevenly. The stresses and deformations near the bed joint are higher than in the middle of the unit (4 pav). 2) From experimental data it was determined that the deformation of bed joints mostly depend on contact zone between units and mortar. The contact zone deformation contains about 80…90% of all bed joint deformation. 3) The elastic modulus of mortar inside the composite is different from modulus of mortar specimens cast separately due to different laying and curing conditions. The elastic modulus values performed from composite were 15…25 times less than the values from standard mortar prisms (EN 1015-11). It is advisable to use real (defined from experiments) masonry units and mortar properties when detailed, numerical stress-strain analysis is performed. 4) Experimental analysis showed that bed joints have big influence to vertical deformation of masonry in axial compression. Masonry units have influence to mechanical properties of mortar joints. The experiment was carried out, during which dry and wet masonry units were used. Units were wet out to eliminate there absorption characteristics. Extra wet out units had an effect to the stiffness of bed joints (12 pav).


1991 ◽  
Vol 113 (3) ◽  
pp. 283-289 ◽  
Author(s):  
R. J. Stango ◽  
V. Cariapa ◽  
A. Prasad ◽  
S.-K. Liang

In the first part of this paper, an experimental system is described which was developed and used for measuring compliant tool performance characteristics. Elementary mechanics considerations and signal-response characteristics of the experimental apparatus for orthogonal brushing are briefly outlined and discussed. The fundamental nature of wire brush stiffness properties and kinetic friction coefficients for orthogonal brush-workpart contact are determined for a range of rotational speeds, and the results are compared to those obtained on the basis of a recently developed (quasi-static) theoretical solution. Discussion is provided concerning three-dimensional filamentary forces which are developed within the contact zone during brush rotation.


2009 ◽  
Vol 1 (4) ◽  
Author(s):  
Donald L. Russell ◽  
Megan McTavish ◽  
Chad E. English

The relationship between the stiffness properties of actuators configured in an agonist-antagonist configuration and the stiffness of the joint is simple but not intuitively obvious. In this paper, this relationship is investigated and it is shown that the stiffness properties (hardening or softening) of the joint depend on the second derivative of the individual actuator stiffness with respect to actuator displacement. Numerical examples are given to illustrate the relationship and two practical examples, in which the actuators stiffness arises from Belleville washers or from an air piston, are analyzed.


2000 ◽  
Vol 14 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Joni Kettunen ◽  
Niklas Ravaja ◽  
Liisa Keltikangas-Järvinen

Abstract We examined the use of smoothing to enhance the detection of response coupling from the activity of different response systems. Three different types of moving average smoothers were applied to both simulated interbeat interval (IBI) and electrodermal activity (EDA) time series and to empirical IBI, EDA, and facial electromyography time series. The results indicated that progressive smoothing increased the efficiency of the detection of response coupling but did not increase the probability of Type I error. The power of the smoothing methods depended on the response characteristics. The benefits and use of the smoothing methods to extract information from psychophysiological time series are discussed.


1997 ◽  
Vol 36 (04/05) ◽  
pp. 237-240
Author(s):  
P. Hammer ◽  
D. Litvack ◽  
J. P. Saul

Abstract:A computer model of cardiovascular control has been developed based on the response characteristics of cardiovascular control components derived from experiments in animals and humans. Results from the model were compared to those obtained experimentally in humans, and the similarities and differences were used to identify both the strengths and inadequacies of the concepts used to form the model. Findings were confirmatory of some concepts but contrary to some which are firmly held in the literature, indicating that understanding the complexity of cardiovascular control probably requires a combination of experiments and computer models which integrate multiple systems and allow for determination of sufficiency and necessity.


2020 ◽  
Vol 23 (3) ◽  
pp. 306-311
Author(s):  
Yu. Kurochkin ◽  
Dz. Shoukavy ◽  
I. Boyarina

The immobility of the center of mass in spaces of constant curvature is postulated based on its definition obtained in [1]. The system of two particles which interact through a potential depending only on the distance between particles on a three-dimensional sphere is considered. The Hamilton-Jacobi equation is formulated and its solutions and trajectory equations are found. It was established that the reduced mass of the system depends on the relative distance.


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