scholarly journals On an experimental method for the solution of plane stress problems

1—Many cases of plane stress distribution which are of importance to the engineer, present problems of mathematical analysis which are intractable and it becomes necessary to rely for a solution either on approximations, which are often crude, or on experimental methods. Perhaps the best known of these experimental methods is that of photoelastic analysis developed by Coker and Filon ; but this requires a wellequipped laboratory and considerable experience in technique if reliable results are to be obtained.

Author(s):  
Tim Oliver ◽  
Akira Ishihara ◽  
Ken Jacobsen ◽  
Micah Dembo

In order to better understand the distribution of cell traction forces generated by rapidly locomoting cells, we have applied a mathematical analysis to our modified silicone rubber traction assay, based on the plane stress Green’s function of linear elasticity. To achieve this, we made crosslinked silicone rubber films into which we incorporated many more latex beads than previously possible (Figs. 1 and 6), using a modified airbrush. These films could be deformed by fish keratocytes, were virtually drift-free, and showed better than a 90% elastic recovery to micromanipulation (data not shown). Video images of cells locomoting on these films were recorded. From a pair of images representing the undisturbed and stressed states of the film, we recorded the cell’s outline and the associated displacements of bead centroids using Image-1 (Fig. 1). Next, using our own software, a mesh of quadrilaterals was plotted (Fig. 2) to represent the cell outline and to superimpose on the outline a traction density distribution. The net displacement of each bead in the film was calculated from centroid data and displayed with the mesh outline (Fig. 3).


2015 ◽  
Vol 41 (3) ◽  
pp. 258-263 ◽  
Author(s):  
Angélica Castro Pimentel ◽  
Marcello Roberto Manzi ◽  
Cristiane Ibanhês Polo ◽  
Claudio Luiz Sendyk ◽  
Maria da Graça Naclério-Homem ◽  
...  

The aim of this study was to evaluate the stress distribution of different retention systems (screwed, cemented, and mixed) in 5-unit implant-supported fixed partial dentures through the photoelasticity method. Twenty standardized titanium suprastructures were manufactured, of which 5 were screw retained, 5 were cement retained, and 10 were mixed (with an alternating sequence of abutments), each supported by 5 external hexagon (4.0 mm × 11.5 mm) implants. A circular polariscope was used, and an axial compressive load of 100 N was applied on a universal testing machine. The results were photographed and qualitatively analyzed. We observed the formation of isochromatic fringes as a result of the stresses generated around the implant after installation of the different suprastructures and after the application of a compressive axial load of 100 N. We conclude that a lack of passive adaptation was observed in all suprastructures with the formation of low-magnitude stress in some implants. When cemented and mixed suprastructures were subjected to a compressive load, they displayed lower levels of stress distribution and lower intensity fringes compared to the screwed prosthesis.


Orthopedics ◽  
1992 ◽  
Vol 15 (12) ◽  
pp. 1445-1450
Author(s):  
Joo-Chul Ihn ◽  
Myun-Whan Ahn ◽  
Dae-Mang Kim

1955 ◽  
Vol 22 (2) ◽  
pp. 255-259
Author(s):  
H. T. Johnson

Abstract An approximate solution for the distribution of stresses in a rotating prismatic shaft, of triangular cross section, is presented in this paper. A general method is employed which may be applied in obtaining approximate solutions for the stress distribution for rotating prismatic shapes, for the cases of either generalized plane stress or plane strain. Polynomials are used which exactly satisfy the biharmonic equation and the symmetry conditions, and which approximately satisfy the boundary conditions.


2013 ◽  
Vol 13 (2) ◽  
Author(s):  
Wati Oviana ◽  
Maulidar Maulidar

The research on the use of experimental methods in learning characteristics of material and its usefulness toward students’ achievements and learning responses of Level 4 primary school students of MIN Tungkob Aceh Besar aims to determine students’ learning outcomes and responses toward the use of the method. This study uses experimental research. The data collection techniques were using test and distributing questionnaire to the students. The samples in this experimental study were students of class IV3 totaling 34 people as the experimental class and the class IV4 totaling 31 people as the control class. The data, which is the students’ learning outcomes collected from pretest and posttest, were analyzed using t-test formula. The data from the students’ questionnaire responses were analyzed using percentage formula.The result was that the students’ learning outcomes from the experimental class and the control class showed significant differences. Students’ responses toward the use of experimental methods in learning material characteristics and its usefulness were also very positive, where the students are very excited and interested in learning to use the experimental method in the study of material characteristics and its usefulness.


1979 ◽  
Vol 21 (5) ◽  
pp. 363-365
Author(s):  
P. K. Datta

The results of analytically and experimentally determined buckling loads of a rectangular plate, subjected to partial edge loading and mixed boundary conditions, are presented.


2014 ◽  
Vol 40 (2) ◽  
pp. 117-122 ◽  
Author(s):  
Eduardo Piza Pellizzer ◽  
Rafael Imai Carli ◽  
Rosse Mary Falcón-Antenucci ◽  
Fellippo Ramos Verri ◽  
Marcelo Coelho Goiato ◽  
...  

The aim of this study was to evaluate stress distribution with different implant systems through photoelasticity. Five models were fabricated with photoelastic resin PL-2. Each model was composed of a block of photoelastic resin (10 × 40 × 45 mm) with an implant and a healing abutment: model 1, internal hexagon implant (4.0 × 10 mm; Conect AR, Conexão, São Paulo, Brazil); model 2, Morse taper/internal octagon implant (4.1 × 10 mm; Standard, Straumann ITI, Andover, Mass); model 3, Morse taper implant (4.0 × 10 mm; AR Morse, Conexão); model 4, locking taper implant (4.0 × 11 mm; Bicon, Boston, Mass); model 5, external hexagon implant (4.0 × 10 mm; Master Screw, Conexão). Axial and oblique load (45°) of 150 N were applied by a universal testing machine (EMIC-DL 3000), and a circular polariscope was used to visualize the stress. The results were photographed and analyzed qualitatively using Adobe Photoshop software. For the axial load, the greatest stress concentration was exhibited in the cervical and apical thirds. However, the highest number of isochromatic fringes was observed in the implant apex and in the cervical adjacent to the load direction in all models for the oblique load. Model 2 (Morse taper, internal octagon, Straumann ITI) presented the lowest stress concentration, while model 5 (external hexagon, Master Screw, Conexão) exhibited the greatest stress. It was concluded that Morse taper implants presented a more favorable stress distribution among the test groups. The external hexagon implant showed the highest stress concentration. Oblique load generated the highest stress in all models analyzed.


2020 ◽  
Vol 6 (2) ◽  
pp. 199-204
Author(s):  
Mila Armiati ◽  
Ahmad Harjono ◽  
Susilawati Susilawati

This research was aim to identify the effect of meaningful instructional design (MID) learning model through experimental methods on mastering the concept of harmonic vibration. This type of research was quasi experiment with nonequivalent control group design with pre-test and post-test. The population was all students class X MIA SMAN 7 Mataram in the academic year 2018/2019 with a purposive sampling technique. Class X MIA 4 was chosen as the experimental class with MID learning model through the experimental method and class X MIA 5 as the control class with conventional learning. Concept mastery data were analyzed using the polled variance t-test. The results of the analysis were tcount>ttable (4.39 > 2.00) at a significant level of 5% which means that Ha was accepted and H0 was rejected. Concluded that there was the effect of the meaningful instructional design (MID) learning model through the experimental method of mastering the concept of harmonic vibration


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