Biomechanical and Elastographic Analysis of Mesenchymal Stromal Cell Treated Tissue Following Surgery

2010 ◽  
Vol 132 (7) ◽  
Author(s):  
Hazel Marie ◽  
Yong Zhang ◽  
Jeremy Heffner ◽  
Heath A. Dorion ◽  
Diana L. Fagan
Keyword(s):  
Mechanical Property ◽  
Tensile Test ◽  
Tensile Testing ◽  
Recovery Period ◽  
Strain Analysis ◽  
Biomechanical Properties ◽  
Uniaxial Tensile ◽  
Uniaxial Tensile Test ◽  
Ongoing Research ◽  
Uniaxial Tensile Testing

Hernia repair continues to be a problem facing surgeons today, particularly because of the high incidence of reoccurrence. This work presents preliminary data of a pioneering effort to investigate the effect of mesenchymal stromal cells (MSCs) on mechanical property enhancement in full thickness fascial defects. Heparinized MSCs harvested from a rabbit’s tibia/iliac crest were applied to two fascial defects on the rabbit’s abdominal wall, with two other defects acting as controls (no MSCs added). After an 8 week recovery period, the entire abdominal fascia was harvested for mechanical property testing and elastographic strain analysis. Preliminary results from uniaxial tensile testing indicate a significant increase in the modulus of toughness strain energy, with at least a 50% increase in the MSC treated defects as compared with the control defects. Results from the elastographic strain analysis show excellent correlation in the calibration of the elastography to the uniaxial tensile test, with nearly identical moduli of elasticity. In addition, the elastographs clearly show tissue property heterogeneity at all stages of tensile testing. The MSC treated tissue demonstrates promise of enhanced material properties over that of the nontreated tissue; testing and analysis is ongoing. The elastography provides pixel-level description of tissue property variations providing critical information on wound healing effectiveness that would be impossible with other methods. In the ongoing research, optical elastography, in combination with the traditional tensile test and tissue histology, will be used to characterize localized biomechanical properties directly within the defect area and to locate “crack” initiation and propagation sights as the material is strained to rupture.

SMALL PUNCH TESTING: AN ALTERNATIVE TESTING TECHNIQUE TO EVALUATE TENSILE BEHAVIOR OF CORTICAL BONE

2017 ◽  
Vol 17 (06) ◽  
pp. 1750102
Author(s):  
JAGJIT SINGH ◽  
N. K. SHARMA ◽  
SATBIR S. SEHGAL
Keyword(s):  
Elastic Modulus ◽  
Tensile Test ◽  
Cortical Bone ◽  
Uniaxial Tensile ◽  
Uniaxial Tensile Test ◽  
Testing Technique ◽  
Bone Material ◽  
Small Punch ◽  
Uniaxial Tensile Testing ◽  
Deformational Behavior

The tensile properties of cortical bone are usually determined with the help of uniaxial tensile test which requires enough amount of bone material. Further, it is very complicated to examine the heterogeneity and anisotropy associated with the deformational properties of cortical bone with the help of uniaxial tensile test. Through this study, small punch testing has been proposed as an alternate technique to evaluate the deformational behavior of cortical bone utilizing optimum amount of bone material. The comparison between elastic modulus values obtained from tensile test and stiffness values obtained through small punch testing was done for validation. The values of these properties were found to be having a significant positive correlation with each other. The effects of bone density and compositional parameters on these properties were also found to be having a similar trend. It is observed through this study that stiffness values from small punch technique are having a similarity with elastic modulus values from uniaxial tensile testing. It is proposed that small punch testing technique can be used as an alternate to examine the deformational behavior of cortical bone.

scholarly journals In Situ Macroscopic Tensile Testing in SEM and Electron Channeling Contrast Imaging: Pencil Glide Evidenced in a Bulk β-Ti21S Polycrystal

Materials ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2479
Author(s):  
Meriem Ben Haj Slama ◽  
Nabila Maloufi ◽  
Julien Guyon ◽  
Slim Bahi ◽  
Laurent Weiss ◽  
...  
Keyword(s):  
Tensile Testing ◽  
Uniaxial Tensile ◽  
Uniaxial Tensile Test ◽  
Contrast Imaging ◽  
Bulk Specimen ◽  
Electron Channeling ◽  
Uniaxial Tensile Testing ◽  
Stress States ◽  
Tangled Dislocation

In this paper, we report the successful combination of macroscopic uniaxial tensile testing of bulk specimen combined with In situ dislocation-scale observations of the evolution of deformation microstructures during loading at several stress states. The dislocation-scale observations were performed by Accurate Electron Channeling Contrast Imaging in order to follow the defects evolution and their interactions with grain boundaries for several regions of interest during macroscopic loading. With this novel in situ procedure, the slip systems governing the deformation in polycrystalline bulk β-Ti21S are tracked during the macroscopic uniaxial tensile test. For instance, curved slip lines that are associated with “pencil glide” phenomenon and tangled dislocation networks are evidenced.

Numerical Simulations and Experimental Results of Tensile Test Behavior of Laser Butt Welded DP980 Steels

2008 ◽  
Vol 130 (4) ◽  
Author(s):  
S. K. Panda ◽  
N. Sreenivasan ◽  
M. L. Kuntz ◽  
Y. Zhou
Keyword(s):  
Tensile Test ◽  
Numerical Simulations ◽  
Tensile Testing ◽  
High Strength Steels ◽  
High Strength ◽  
Experimental Results ◽  
Uniaxial Tensile ◽  
Vehicle Performance ◽  
Soft Zone ◽  
Uniaxial Tensile Testing

Laser welding of advanced high strength steels for fabrication of tailor welded blanks is of increasing interest for continued improvements in vehicle performance and safety without an increase in weight. Experimental results have shown that formability of welded dual-phase (DP) steels is significantly reduced by the formation of a softened region in the heat-affected zone (HAZ). In this study, a finite element simulation of welded DP980 samples undergoing transverse uniaxial tensile testing was used to evaluate the effects of soft zone width and strength on formability characteristics. Both the strength and the ductility of laser welded blanks decreased compared with those of unwelded blanks due to the formation of a softened outer-HAZ, where strain localization and final fracture occurred during tensile testing. The magnitude of softening and the width of the HAZ depend on the laser specific energy. It was observed from tensile test experiments and numerical simulations that both a decrease in strength and an increase in width of the softened HAZ were responsible for a decrease in the overall strength and ductility of the welded blanks.

Tensile Testing for Determining Sheet Formability

2004 ◽  
pp. 101-114
Keyword(s):  
Tensile Test ◽  
Plane Strain ◽  
Sheet Metal ◽  
Tensile Testing ◽  
Large Family ◽  
Uniaxial Tensile ◽  
Uniaxial Tensile Test ◽  
Accurate Indication ◽  
Complex Shapes ◽  
Sheet Formability

Abstract Sheet metal forming operations consist of a large family of processes, ranging from simple bending to stamping and deep drawing of complex shapes. Because sheet forming operations are so diverse in type, extent, and rate, no single test provides an accurate indication of the formability of a material in all situations. However, as discussed in this chapter, the uniaxial tensile test is one of the most widely used tests for determining sheet metal formability. This chapter describes the effect of material properties and temperature on sheet metal formability. Information on the types of formability tests is also provided. The chapter discusses the processes involved in uniaxial and plane-strain tensile testing. Examples include the uniaxial tensile test and the plane-strain tensile test which are subsequently described.

Mechanical behavior of chemically treated ostrich pericardium subjected to uniaxial tensile testing: influence of the suture

2002 ◽  
Vol 62 (1) ◽  
pp. 73-81 ◽  
Author(s):  
J. M. García Páez ◽  
A. Carrera ◽  
E. Jorge Herrero ◽  
I. Millán ◽  
A. Rocha ◽  
...  
Keyword(s):  
Mechanical Behavior ◽  
Tensile Testing ◽  
Uniaxial Tensile ◽  
Uniaxial Tensile Testing ◽  
Chemically Treated

Tensile Testing

2004 ◽  
Keyword(s):  
Tensile Testing ◽  
Uniaxial Tensile ◽  
Uniaxial Tensile Test ◽  
Bonded Joints ◽  
Adhesively Bonded ◽  
Adhesively Bonded Joints ◽  
Design And Manufacturing ◽  
Data Tables ◽  
Reference Section

Tensile Testing, Second Edition is a comprehensive guide to the uniaxial tensile test and its use in determining the mechanical properties and behaviors of materials. The first six chapters cover the fundamentals of tensile testing, including the methodology, the equipment used, the effect of tensile loading on metals, the interpretation of data, and the role of tensile testing in design and manufacturing. The next six chapters deal with the testing of different classes of engineering materials, namely metals, plastics, elastomers, ceramics, and composites, and fabricated structures such as weldments and bolted and adhesively bonded joints. The book also includes three chapters on the nuances of tensile testing at extreme temperatures and strain rates and a reference section with data tables. For information on the print version, ISBN 978-0-87170-806-9, follow this link.

A Novel MEMS-Based Technique for In-Situ Characterization of Freestanding Nanometer Scale Thin Films Inside SEM and TEM

2001 ◽  
Author(s):  
M. A. Haque ◽  
M. T. A. Saif
Keyword(s):  
Thin Films ◽  
Tensile Testing ◽  
Uniaxial Tensile ◽  
Aluminum Specimen ◽  
Sem And Tem ◽  
Uniaxial Tensile Testing ◽  
Testing Facility ◽  
Film Specimen ◽  
On Chip

Abstract We present a MEMS-based technique for in-situ uniaxial tensile testing of freestanding thin films inside SEM and TEM. It integrates a freestanding thin film specimen with MEMS force sensors and structures to produce an on-chip tensile testing facility. Cofabrication of the specimen with force and displacement measuring mechanisms produces the following unique features: 1) Quantitative experimentation can be carried out in both SEM and TEM, 2) No extra gripping mechanism is required, 3) Specimen misalignment can be eliminated, 4) Pre-stress in specimen can be determined, and 5) Specimens with micrometer to nanometer thickness can be tested. We demonstrate the technique by testing a 200-nanometer thick Aluminum specimen in-situ in SEM. Significant strengthening and anelasticity were observed at this size scale.

scholarly journals Length Scale and Aging Effect on the Mechanical Properties of a 63Sn-37Pb Solder Alloy

2000 ◽  
Author(s):  
T. Jesse Lim ◽  
Wei-Yang Lu
Keyword(s):  
Ultimate Strength ◽  
Tensile Testing ◽  
Failure Strain ◽  
Aging Effect ◽  
Uniaxial Tensile ◽  
Strain Response ◽  
Stress Strain ◽  
Uniaxial Tensile Testing ◽  
Aging Conditions ◽  
Strain Responses

Abstract In this work, uniaxial tensile testing of a 63Sn-37Pb alloy with different specimen sizes and aging conditions had been carried out. Although the stress-strain responses of different specimen sizes and aging conditions differs, the ultimate strength of the specimens with 16 hours, 100°C aging are similar for the sizes tested. The specimens with 25 days, 100°C aging have different stress-strain response with different sizes, and have a lower ultimate strength and higher failure strain compared to 16 hours, 100°C aging specimens.

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