A Triaxial-Measurement Shear-Test Device for Soft Biological Tissues

2000 ◽  
Vol 122 (5) ◽  
pp. 471-478 ◽  
Author(s):  
Socrates Dokos ◽  
Ian J. LeGrice ◽  
Bruce H. Smaill ◽  
Julia Kar ◽  
Alistair A. Young
Keyword(s):  
Shear Test ◽  
Biological Tissues ◽  
Living Tissue ◽  
Test Device ◽  
Shear Tests ◽  
Shear Deformations ◽  
Material Parameters ◽  
Independent Test ◽  
Shear Characteristics ◽  
Septal Myocardium

A novel shear-test device for soft biological tissue, capable of applying simple shear deformations simultaneously in two orthogonal directions while measuring the resulting forces generated in three axes, is described. We validated the device using a synthetic gel, the properties of which were ascertained from independent tensile and rotational shear tests. Material parameters for the gel were fitted using neo-Hookean analytical solutions to the independent test data, and these matched the results from the device. Preliminary results obtained with rat septal myocardium are also presented to demonstrate the feasibility of the apparatus in determining the shear characteristics of living tissue. [S0148-0731(00)00205-3]

scholarly journals Sand- and Clay-Photocured-Geomembrane Interface Shear Characteristics Using Direct Shear Test

2021 ◽  
Vol 13 (15) ◽  
pp. 8201
Author(s):  
Lihua Li ◽  
Han Yan ◽  
Henglin Xiao ◽  
Wentao Li ◽  
Zhangshuai Geng
Keyword(s):  
Soil Surface ◽  
Friction Angle ◽  
Direct Shear ◽  
Tensile Crack ◽  
Shear Tests ◽  
Interface Shear ◽  
Direct Shear Tests ◽  
Carbon Black Powder ◽  
Shear Characteristics ◽  
Impermeable Layer

It is well known that geomembranes frequently and easily fail at the seams, which has been a ubiquitous problem in various applications. To avoid the failure of geomembrane at the seams, photocuring was carried out with 1~5% photoinitiator and 2% carbon black powder. This geomembrane can be sprayed and cured on the soil surface. The obtained geomembrane was then used as a barrier, separator, or reinforcement. In this study, the direct shear tests were carried out with the aim to investigate the interfacial characteristics of photocured geomembrane–clay/sand. The results show that a 2% photoinitiator has a significant effect on the impermeable layer for the photocured geomembrane–clay interface. As for the photocured geomembrane–sand interface, it is reasonable to choose a geomembrane made from a 4% photoinitiator at the boundary of the drainage layer and the impermeable layer in the landfill. In the cover system, it is reasonable to choose a 5% photoinitiator geomembrane. Moreover, as for the interface between the photocurable geomembrane and clay/sand, the friction coefficient increases initially and decreases afterward with the increase of normal stress. Furthermore, the friction angle of the interface between photocurable geomembrane and sand is larger than that of the photocurable geomembrane–clay interface. In other words, the interface between photocurable geomembrane and sand has better shear and tensile crack resistance.

scholarly journals Shear Tests and Calculation of Shear Resistance with the PC Program RFEM from Thin Partition Walls of Brick in Old Buildings

2015 ◽  
Vol 10 (2) ◽  
pp. 103-112
Author(s):  
Sinan Korjenic ◽  
Bernhard Nowak ◽  
Philipp Löffler ◽  
Anna Vašková
Keyword(s):  
Horizontal Displacement ◽  
Shear Resistance ◽  
Shear Capacity ◽  
Horizontal Force ◽  
Shear Tests ◽  
Maximum Displacement ◽  
Existing Building ◽  
Material Parameters ◽  
Partition Walls ◽  
Material Studies

Abstract This paper is about the shear capacity of partition walls in old buildings based on shear tests which were carried out under real conditions in an existing building. There were experiments conducted on different floors and in each case, the maximum recordable horizontal force and the horizontal displacement of the respective mortar were measured. At the same time material studies and material investigations were carried out in the laboratory. The material parameters were used for the calculation of the precise shear capacity of each joint. In the shear tests, the maximum displacement of a mortar joint was determined at a maximum of two to four millimetres. Furthermore, no direct linear relationship between the theoretical load (wall above it) and the shear stress occurred could be detected in the analysis of the experiment, as it was previously assumed.

Numerical Simulation of Interface Softening for Large Size Direct Shear Test

2011 ◽  
Vol 368-373 ◽  
pp. 3230-3235
Author(s):  
Zhao Yun Xiao ◽  
Wei Xu ◽  
Yan Sheng Deng ◽  
Fan Tu
Keyword(s):  
Numerical Simulation ◽  
Direct Shear Test ◽  
Shear Test ◽  
Friction Model ◽  
Secondary Development ◽  
Direct Shear ◽  
Shear Tests ◽  
Direct Shear Tests ◽  
Softening Behavior ◽  
Large Size

The interface of non-woven geotextile and HDPE geomembrane based on direct shear test has an obvious softening behavior. This paper adopts displacement-softening model that proposed by Esterhuizen and conducts secondary development by using ABAQUS and its embedded FRIC subroutine, making further efforts to conduct numerical simulation of interface of non-woven geotextile and HDPE geomembrane based on large-size direct shear tests. Results show that the developed interface friction model can simulate the characteristics of interface softening of certain materials better, thus providing a method when study the interface softening characteristic of materials.

Wire Bond Shear Test Simulation on Sharp Groove Surface Bond Pad

2012 ◽  
Vol 622-623 ◽  
pp. 647-651 ◽  
Author(s):  
Z. Sauli ◽  
V. Retnasamy ◽  
S. Taniselass ◽  
A.H.M. Shapri ◽  
R. Vairavan
Keyword(s):  
Stress Response ◽  
Shear Test ◽  
Copper Wire ◽  
Gold Wire ◽  
Shear Tests ◽  
Groove Surface ◽  
Wire Bond ◽  
Packaging Industry ◽  
Semiconductor Packaging ◽  
Surface Bond

Wire bonding process is first level interconnection technology used in the semiconductor packaging industry. The wire bond shear tests are used in the industry to examine the bond strength and reliability of the bonded wires. Hence, in this study thesimulation on wire bond shear test is performed on a sharp groove surface bond pad. ANSYS ver 11 was used to perform the simulation. The stress response of the bonded wires are investigated.The effects of three wire materials gold(Au), aluminum(Al) and copper(Cu) on the stress response during shear test were examined. The simulation results showed that copper wire bond induces highest stress and gold wire exhibits the least stress response.

Material Issues of Low Temperature Co-fired Ceramic (LTCC) Fine Pitch Chip Scale Package (CSP) Designs

2003 ◽  
Vol 783 ◽  
Author(s):  
Megan M. Owens ◽  
Joseph W. Soucy ◽  
Thomas F. Marinis ◽  
Kevin A. Bruff ◽  
Henry G. Clausen
Keyword(s):  
Shear Test ◽  
Solder Ball ◽  
Ball Grid Array ◽  
Substrate Material ◽  
Test Results ◽  
Shear Tests ◽  
Fine Pitch ◽  
Test Board ◽  
Chip Scale Package ◽  
Ltcc Substrate

ABSTRACTLTCC substrates for fine pitch (1.0 mm and 0.8 mm) CSP applications have been designed, fabricated, and assembled. The assembly process, including ball grid array (BGA) solder ball attach, die mount, wire bond, and glob top is described. The material and physical design interaction issues that emerged during development are discussed.The initial CSP design was conventional, with co-fired yellow gold (Au) vias and capture pads and post-fired solderable gold (PtPdAu) pads for solder ball attachment. Because LTCC tape shrinks during co-fire, solder pads were applied post co-fire to ensure proper mating with existing test fixtures and to provide the best alignment relative to the CSP body. Solder pad to capture pad misalignment was visible following solder pad firing. After CSP attachment to a test board, electrical tests revealed opens. Investigation led to the following conclusions. The decreased solder pad diameter necessary to accommodate the fine pitch design was significant relative to the area allocated for the underlying via and capture pad. Misalignment that would have been hidden under larger solder pads was exposed. Even when the capture pad surface was not visibly exposed, the offset solder pad meant less material between the capture pad and the solder ball, less of a barrier to solder leaching. Solder leaching into the yellow gold, observed after CSP removal from the test board, was the cause of the electrical disconnects. In the second design, the capture pad was eliminated in order to discourage leaching by reducing the volume of yellow gold available to alloy with the solder pad during co-fire. Reflow operations still resulted in leached solder pads. A third design replaced the first-layer via yellow gold with a solderable gold. This design proved to be robust.While developing designs and fabricating these prototypes, it was noted that all ball failures consistently occurred between the solder pad and the LTCC substrate. To investigate adhesion using different metallizations, shear tests were performed on LTCC substrates with either post-fired solder pads or co-fired pads. To investigate how the substrate material affects adhesion, alumina CSPs were also sheared. Shear test results are presented.

A Contribution to the Optimisation of a Simple Shear Test

2009 ◽  
Vol 410-411 ◽  
pp. 467-472 ◽  
Author(s):  
Marion Merklein ◽  
M. Biasutti
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Shear Test ◽  
The Finite Element Method ◽  
Simple Shear Test ◽  
Material Parameters

The finite element method is a widely used tool in sheet metal forming. The quality of the results of such an analysis depends largely on the applied constitutive model and its material parameters, which have to be determined experimentally. These data are relevant on the choice of the yield criterion among the wide range of options available in the commercial applications implementing the finite element method. Since the accuracy of material parameters estimation is therefore crucial, investigations were performed with an Al-Mg sheet alloy and a mild steel sheet to optimize a Miyauchi-based simple shear test. This method is one of the basic ways to investigate the plastic properties of a sheet metal up to large strains, which is very important for numerical analysis of sheet metal forming processes. Aim of the test is to determine the shear stress-strain correlation. In order to enhance the quality of the experimental results the detection of the deformation’s field, trough an optical measurement system, and the methodology for its evaluation are focus of the present study.

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