A Nondestructive Three-Dimensional Strain-Analysis Method

1961 ◽  
Vol 28 (1) ◽  
pp. 83-86 ◽  
Author(s):  
A. J. Durelli ◽  
I. M. Daniel
Keyword(s):  
Stress Analysis ◽  
Three Dimensional ◽  
Strain Analysis ◽  
Good Precision ◽  
Analysis Method ◽  
Strain Fields ◽  
Nondestructive Determination

The objective of this paper is to develop the technique of the embedded grid for three-dimensional strain and stress analysis. The application to the case of a sphere subjected to diametral loading is described and results are compared with theoretical and photoelastic ones. The limitations of the method are outlined and suggestions for improvement made. As it stands now, the method allows the nondestructive determination of three-dimensional strain fields with good precision. The determination of stresses, however, is less precise.

Adequate Strength for Small High-Speed Vessels

1968 ◽  
Vol 5 (01) ◽  
pp. 63-71
Author(s):  
Philip J. Danahy
Keyword(s):  
Stress Analysis ◽  
High Speed ◽  
Structural Strength ◽  
Integrated Approach ◽  
Suggested Method ◽  
Impact Loads ◽  
Analysis Method ◽  
Safety Factors ◽  
Recreational Vessels

The paper presents a method for the determination of the critical minimum scantlings for small high-speed vessels. Particular attention is given to the shell plating strength for hydrodynamic impact loads. The suggested method uses an integrated approach involving assumed loads, suggested safety factors, and preferred stress-analysis method. The stress analysis uses plastic theory based partly on the works of J. Clarkson and Thein Wah. Included in the paper is a comparison of the relative structural strength of several commercial, military, and experimental hydrofoil vessels along with a few planing boats and a seaplane hull. This shows the variation of existing vessel structures and compares them to the results obtained by the suggested method. Most commercial, military, and recreational vessels exceed the minimum scantlings of the suggested method. The most significant deviation is the hull of the seaplane:

Simulation of stress and strain analysis on a delimbing knife with replaceable cutting edge

BioResources ◽  
2020 ◽  
Vol 15 (2) ◽  
pp. 3799-3808
Author(s):  
Ján Melicherčík ◽  
Jozef Krilek ◽  
Pavol Harvánek
Keyword(s):  
Finite Element Method ◽  
Stress Analysis ◽  
Cutting Force ◽  
Woody Plants ◽  
Strain Analysis ◽  
Cutting Edge ◽  
Stress And Strain ◽  
Cutting Knife ◽  
Basic Parameters

This study focused on stress and strain analysis of the cutting force of a branch knife with a replaceable cutting edge. The replaceable edge forms part of the delimbing head, which is applied to the arms of a mechanical harvester working in forestry. Basic parameters of the knife and head of the harvester with the basic calculations necessary to determine the number of knives based on input parameters, such as wood diameter, woody plants, and determination of the cutting force acting on the cutting knife, were examined. Based on the cutting force and the design of the special cutting knife, a stress analysis and a finite element method (FEM) was performed. This study confirmed the correctness of the selected material to produce the delimbing knife, which was designed using a replaceable cutting edge. The output of the stress analysis is reported.

The stress analysis method for three-dimensional composite materials

1994 ◽  
Vol 1 (3) ◽  
pp. 197-216 ◽  
Author(s):  
Kanehiro Nagai ◽  
Atsushi Yokoyama ◽  
Zen'ichiro Maekawa ◽  
Hiroyuki Hamada
Keyword(s):  
Composite Materials ◽  
Stress Analysis ◽  
Three Dimensional ◽  
Analysis Method

A Photoelastic Study of Stresses in Rotating Disks

1940 ◽  
Vol 7 (2) ◽  
pp. A57-A60
Author(s):  
R. E. Newton
Keyword(s):  
Stress Analysis ◽  
Fringe Pattern ◽  
Three Dimensional ◽  
New Technique ◽  
Uniform Thickness ◽  
Rotating Disks ◽  
Photoelastic Method ◽  
Freezing Method ◽  
Stress Freezing Method

Abstract The recent experiments of Hetényi and others in developing a technique for “freezing” stresses in bakelite and other photoelastic plastics have broadened tremendously the scope of the photoelastic method of stress analysis. In addition to making possible the solution of three-dimensional problems, the new technique offers itself as a powerful tool in solving problems in which it is inconvenient to study the fringe pattern while the model is actually under load. Problems of centrifugal stresses in constant-speed rotors fall in this class and are readily handled by the stress-freezing method. It is the purpose of this paper to discuss the application of the technique to the determination of the stresses in rotating disks of uniform thickness having symmetrically placed noncentral holes, as shown in Fig. 1 (1, 2).

Finite Element Analysis for Pin-Hole-Output Mechanism of FA Cycloid Drive Based on ANSYS

2011 ◽  
Vol 308-310 ◽  
pp. 2220-2223 ◽  
Author(s):  
Lei Lei ◽  
Ying Tao ◽  
Tian Min Guan
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Analysis ◽  
Three Dimensional ◽  
Element Model ◽  
Analysis Method ◽  
Element Analysis ◽  
Analysis Theory ◽  
Calculation Results ◽  
Dynamic Stress Analysis

In order to validate the pin-hole-output mechanism of FA cycloid drive force analysis theory, and based on the study on the basis of the contact problem, this article used the international advanced finite element analysis software ANSYS, established the output dowel pin and cycloid gear pin hole's contacting finite element model, and analyzed the static three-dimensional contact analysis. The calculation results coincided with the proposed pin-hole-output mechanism with gap dynamic stress analysis method, proved the correctness of the stress analysis theory.

FEM Stress Analysis of Tee Intersections With LTA

2008 ◽  
Author(s):  
T. Ahmad ◽  
M. Qadir ◽  
D. Redekop
Keyword(s):  
Stress Analysis ◽  
Three Dimensional ◽  
Local Area ◽  
Collapse Load ◽  
Wall Thinning ◽  
Dimensional Finite Element ◽  
Cyclical Loading ◽  
Different Depths ◽  
Three Dimensional Finite Element

In this work a three-dimensional finite element study is carried out of pressurized piping tee (tee) intersections, with local area wall thinning (LTA). Two types of stress analysis are carried out, dealing respectively with the determination of the stress concentration factor (SCF), and of the plastic collapse load. Stress values determined for vessels with uniform thickness are compared with previously published work. An evaluation is then made of the effect on the SCF values of varying the size and shape of the LTA around the intersection. This is followed by a parametric study in which the SCF and the collapse load are computed for intersections with different depths of wall thinning. Finally, comments are made on the fatigue of tees with LTA having cyclical loading superimposed on the constant pressure loading.

Yield Strength Determination of TiN Film by In-Situ XRD Stress Analysis Method

2002 ◽  
Vol 404-407 ◽  
pp. 671-676 ◽  
Author(s):  
M. Qin ◽  
Vincent Ji ◽  
Jiu Hua Xu ◽  
J.B. Li ◽  
Ke Wei Xu ◽  
...  
Keyword(s):  
Yield Strength ◽  
Stress Analysis ◽  
Analysis Method ◽  
In Situ Xrd ◽  
Tin Film ◽  
Strength Determination

A three-dimensional graphical method for shear strain analysis

1994 ◽  
Vol 29 (4) ◽  
pp. 263-266
Author(s):  
S E-D Taher ◽  
A A Almusallam
Keyword(s):  
Graphical Method ◽  
Mathematical Formulation ◽  
Three Dimensional ◽  
Strain Analysis ◽  
Graphical Methods ◽  
Strain Components ◽  
Graphical Technique ◽  
Shearing Strain ◽  
Original Construction

The efficiency of graphical methods for strain analysis depends merely on its simplicity and accuracy. For most strain definitions, the Mohr circle has proved to be the most powerful graphical technique. Unfortunately, its three-dimensional form has limitations concerning the determination of the shearing strain components on a general oblique plane. In this paper, the various deformation quantifiers and the existing extensions to Mohr's method which account for its drawbacks are briefly reviewed. A novel proposal to be appended to Mohr's original construction, allowing its complete generality, is given. It has the form of a simplified complementary triangular construction. A mathematical formulation of the suggested graphical techniques on the basis of Cauchy's formula and vector analysis is carried out.

The precision and repeatability of a custom-made pointer device for determination of virtual landmarks in canine three-dimensional kinematics

2012 ◽  
Vol 25 (02) ◽  
pp. 102-108 ◽  
Author(s):  
S. Malek ◽  
G. J. Monteith ◽  
N. M. M. Moens
Keyword(s):  
Average Distance ◽  
Three Dimensional ◽  
Anatomical Landmarks ◽  
Good Precision ◽  
Lateral Epicondyle ◽  
Accuracy And Precision ◽  
Custom Made ◽  
Source Of Error ◽  
Steinmann Pin

SummaryPlacement of markers on anatomical landmarks represents a large source of error in three-dimensional kinematics. Our objectives were to test the accuracy and precision of a custom-made pointer and compare it to conventional skin markers in dogs. The pointer was first assessed by pointing at the surface of a spherical marker of known dimensions and position in space. Secondly, a point located cranio-distally to the lateral epicondyle was marked in 12 canine elbows with a Steinmann pin and reflective markers. Ability to locate a landmark was compared between the pointer and skin-mounted marker. The distance between experimental and true locations was compared between the two methods. A sphere was mathematically fitted through 29 collected points on the spherical marker. Centre, diameter and volume overlap of the fitted sphere were compared to that of the marker. A 0.729 mm bias was found indicating good accuracy. Residual values were small indicating good precision. The average distance between the true and experimental position of the anatomical landmarks were 9.55 ± 4.20 mm and 9.32 ± 3.28 mm for the pointer and the marker respectively. No significant differences were observed between the two methods. The pointer proved to be accurate and reliable for localizing virtual points and was at least equivalent to skin mounted markers for the detection of anatomical landmarks in the dog. It should prove useful in the localization of anatomical landmarks for kinematic analysis.

Sign in / Sign up

Export Citation Format

Share Document