Quadratic isoparametric circular plate element with strain smoothing

1976 ◽  
Vol 11 (2) ◽  
pp. 132-134 ◽  
Author(s):  
A S Mawenya
Keyword(s):  
Shear Stress ◽  
Stress Field ◽  
Least Squares ◽  
Circular Plate ◽  
Stiffness Matrix ◽  
Plate Bending ◽  
Plate Element ◽  
Strain Smoothing ◽  
Shear Effects ◽  
Linear Smoothing

A number of plate bending elements which include shear suffer from spurious shear effects. So far, however, the techniques that have been used to eliminate these effects involve only the manipulation of the stiffness matrix, and are incapable of accurately predicting the distribution of the shear stress resultants within the element. Herewith, a least squares linear smoothing is applied to the strain matrix of a quadratic, isoparametric symmetrical circular plate element before assembling the stiffness matrix; thereby leading to a better prediction of the stress field within the element.

Analysis of the Elastic Contact of a Hollow Ball With a Flat Plate

1970 ◽  
Vol 92 (1) ◽  
pp. 138-142 ◽  
Author(s):  
J. H. Rumbarger ◽  
R. C. Herrick ◽  
P. R. Eklund
Keyword(s):  
Shear Stress ◽  
Stress Field ◽  
Flat Plate ◽  
Normal Load ◽  
Thick Wall ◽  
Elastic Contact ◽  
Solid Ball ◽  
Ball Contact ◽  
Contact Life ◽  
Hollow Ball

This paper presents the analysis of the stress field in a hollow sphere in the vicinity of the contact area. The sphere is subjected to a normal load applied through a flat plate. The elastic contact shape and extent are developed for a load of 1000 lb applied to a 1-in-dia hollow ball with a 0.08-in-thick wall. Hollow ball shell bending stresses have a significant effect upon the subsurface stress field. Fatigue life estimates for the hollow ball vary significantly depending upon the selection of decisive stress amplitude. Comparison of the maximum value and location of the reversing orthogonal subsurface shear stress with solid ball data according to the Lundberg-Palmgren dynamic life theory predicts a 91.6 percent life reduction for the hollow ball contact. The use of the unidirectional subsurface shear stress results in a prediction of hollow ball contact life over 30 times the solid ball contact life.

PERIDYNAMIC UNIT CELL ENABLED FINITE ELEMENT MODELING OF FIBER STEERED COMPOSITES

2021 ◽  
Author(s):  
ERDOGAN MADENCI, ◽  
ATILA BARUT ◽  
NAM PHAN ◽  
ZAFER GURDAL
Keyword(s):  
Finite Element ◽  
Composite Laminates ◽  
Stiffness Matrix ◽  
Unit Cell ◽  
Plate Element ◽  
Finite Element Implementation ◽  
Effective Material Property ◽  
Fiber Path ◽  
Element Shape ◽  
Simple Modeling

This study presents an approach based on traditional finite elements and peridynamic unit cell (PDUC) to perform structural analysis of fiber steered composite laminates. Effective material property matrix for each ply in the plate element is computed by employing the PDUC based on the orientation of the fiber path and orthotropic ply properties. Each element defines the unit cell domain if the element shape is rectangular. Otherwise, the rectangle that circumscribes the element defines the domain of the unit cell. The element stiffness matrix is constructed through a traditional finite element implementation. This approach provides an accurate and simple modeling of variable angle tow laminates. It can be readily integrated in commercially available finite element programs.

Framework Analog for Circular Plate Bending

1977 ◽  
Vol 103 (7) ◽  
pp. 1479-1483
Author(s):  
H. Kinh Ha
Keyword(s):  
Circular Plate ◽  
Plate Bending

Cell adhesion on gaseous plasma modified poly-(l-lactide) surface under shear stress field

Biomaterials ◽  
2003 ◽  
Vol 24 (21) ◽  
pp. 3757-3764 ◽  
Author(s):  
Yuqing Wan ◽  
Jian Yang ◽  
Junlin Yang ◽  
Jianzhong Bei ◽  
Shenguo Wang
Keyword(s):  
Shear Stress ◽  
Cell Adhesion ◽  
Stress Field ◽  
Gaseous Plasma ◽  
Shear Stress Field

An Evaluation of a Modified Iosipescu Specimen for Measurement of Elastic-Plastic Properties of Solder Materials

2010 ◽  
Author(s):  
Subhasis Mukherjee ◽  
Abhijit Dasgupta
Keyword(s):  
Shear Stress ◽  
Stress Field ◽  
Solder Joint ◽  
Scale Effects ◽  
Element Model ◽  
Test Material ◽  
Plastic Properties ◽  
Elastic Plastic ◽  
Uniform Shear ◽  
Shear Stress Field

There are various specimen configurations available in the literature for characterizing the mechanical behavior of solder interconnect materials. An ideal test specimen should use a simple geometry to minimize the complexity of the stress analysis and which produces a uniform material response throughout the test material. In the thermo-mechanical micro scale (TMM) test used in this study, we use a simple, notched shear specimen, based on a concept originally proposed by Iosipescu [1967] [1], which produces a very uniform shear stress field in the solder joint volume [Reinikainen et al., 1998] [2]. Our modified Iosipescu specimen comprises of two oxygen free, high conductivity (OFHC) copper platens soldered together and loaded in simple shear. The solder joint in this specimen is only 180 microns wide to capture the length scale effects of functional solder interconnects. This study examines the effects of dimensional variabilities of this modified Iosipescu specimen on the shear stress distribution in the solder joint. Variabilities encountered in these specimens include: (i) fillets at the V-notches, caused by excess solder; (ii) offset between the two copper platens along the loading direction; (iii) taper of the solder joint due to lack of parallelism of the edges of the copper platens; and (iv) misalignment between the specimen centerline and loading axis of the TMM test frame due to mounting variability. Detailed parametric studies of these four dimensional variations in the TMM specimen are conducted using a simple two-dimensional elastic-plastic finite element model. The uniformity of the shear stress field in the specimen is investigated and the variation in the derived stress-strain curves is examined, as a function of the dimensional variabilities described above.

Linear Static, Real-Time Finite Element Computations Based on Element Masks

2011 ◽  
Author(s):  
Holger Graf ◽  
Andre´ Stork
Keyword(s):  
Finite Element ◽  
Stress Field ◽  
Boundary Conditions ◽  
Real Time ◽  
Stiffness Matrix ◽  
New Method ◽  
Stress Distributions ◽  
Post Processing ◽  
Time Performance ◽  
Computational Overhead

This paper presents a new method for the manipulation of a given CAE domain in view of VR based explorations that enables engineers to interactively inspect and analyze a linear static domain. The interactions can ideally be performed in real-time in order to provide an intuitive impression of the changes to the underlying volumetric domain. We take the approach of element masking, i.e. the blending out of computations resulting from computational overhead for inner nodes, based on the inversion of the stiffness matrix. This allows us to optimize the re-simulation loop and to achieve real-time performance for strain and stress distributions with immediate visualization feedback caused by interactively changing boundary conditions. The novelty of the presented approach is a direct coupling of view dependent simulations and its close linkage to post-processing tasks. This allows engineers to also inspect the changes of the stress field inside of the volume during, e.g. cross sectioning.

scholarly journals Iosipescu Shear Test of Composite Joint Specimens in Tensile Loading

1995 ◽  
Vol 4 (4) ◽  
pp. 096369359500400 ◽  
Author(s):  
Jang-Kyo Kim ◽  
Joo Hyuk Park
Keyword(s):  
Shear Stress ◽  
Stress Field ◽  
Composite Laminates ◽  
Shear Test ◽  
Pure Shear ◽  
Maximum Shear Stress ◽  
Tensile Loading ◽  
Composite Joint ◽  
Loading Method ◽  
Iosipescu Shear Test

The stress field arising in tensile loading of the Iosipescu shear test is analyzed by means of finite element method. In a parametric study on a composite laminates-adhesive joint, the tensile loading method is shown more effective in creating a pure shear stress field with negligible normal stresses in the notched area than the conventional compressive loading method, although the maximum shear stress is marginally higher for the former method than the latter.

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