A Novel MEMS-based Nanoscale Material Testing System

2006 ◽  
Author(s):  
H.D. Espinosa ◽  
Yong Zhu ◽  
A. Corigliano
Keyword(s):  
Material Testing ◽  
Testing System ◽  
Nanoscale Material

In-Situ Electron Microscopy Testing of 1-D Nanostructures

2008 ◽  
Author(s):  
Horacio D. Espinosa
Keyword(s):  
Tensile Testing ◽  
Material Testing ◽  
Testing System ◽  
Device Performance ◽  
Nanoscale Material ◽  
The Past ◽  
In Situ Electron Microscopy ◽  
Experimental Approaches ◽  
Walled Cnts

Over the past decade, there has been a substantial thrust to reduce the size of electronic and electromechanical systems to the nano scale by fabricating devices out of thin films, carbon nanotubes (CNTs) and nanowires (NWs). In these applications, a thorough understanding of material mechanical, electrical and thermal properties as well as device performance and reliability requires the development of novel experimental approaches. In this presentation the design, microfabrication and operation of a MEMS based nanoscale material testing system (n-MTS, see Fig. 1) will be presented. Results obtained from in-situ SEM and TEM tensile testing of NWs and CNTs will be discussed. We will show that TEM imaging is required to properly assess the modulus and strength of multi-walled CNTs (MWCNTs) and demonstrate that the assumption of outer shell failure is not accurate in most cases. We will also discuss a change in failure mode as a function of electron and ion radiation.

Biomechanics of the wrist after proximal row carpectomy in cadavers

2009 ◽  
Vol 35 (1) ◽  
pp. 43-45 ◽  
Author(s):  
Y.-L. Zhu ◽  
Y.-Q. Xu ◽  
J. Ding ◽  
J. Li ◽  
B. Chen ◽  
...  
Keyword(s):  
Sharp Decrease ◽  
Material Testing ◽  
Testing System ◽  
Average Pressure ◽  
Proximal Row Carpectomy ◽  
Pressure Sensitive ◽  
Sensitive Film ◽  
Fresh Frozen ◽  
Pressure Sensitive Film ◽  
Lunate Fossa

We investigated the biomechanics of the radiocapitate joint after a proximal row carpectomy in six fresh-frozen cadaver wrists using super-low-pressure-sensitive film on a material testing system. The average pressure within the lunate fossa increased significantly from 23.2 to 136.4 N/cm2 with a sharp decrease in the contact area from 2.08 to 0.30 cm2 after a proximal row carpectomy. The cartilage of the proximal capitate had four sub-facets and therefore was not as smooth as the normal proximal lunate. We found that the wrist was overloaded after a proximal row carpectomy and the main cause was the anatomical mismatch of the radiocapitate articulation.

THE MECHANICAL BEHAVIOUR OF COBALT SUPERALLOYS WITH TI ELEMENT ADDITION

2013 ◽  
Vol 37 (3) ◽  
pp. 365-373
Author(s):  
Tao-Hsing Chen
Keyword(s):  
Strain Rate ◽  
Mechanical Response ◽  
Rate Sensitivity ◽  
Material Testing ◽  
Testing System ◽  
Strain Rates ◽  
Strengthening Effect ◽  
Microstructural Characteristics ◽  
Element Addition ◽  
Increasing Temperature

The influence of titanium element, strain rate and tested temperatures on the mechanical properties and microstructural characteristics will be investigated in this paper. These cobalt-based superalloys are tested using material testing system (MTS) at strain rates of 10−3, 10−2 and 10−1 s−1 and at temperatures of 700, 500 and 25° C, respectively. It is found that the flow stress increases with increasing strain rate and Ti, but decreases with increasing temperature. Furthermore, the strain rate sensitivity increases with increasing strain rate, but decreases with increasing temperature. The microstructural observations confirm that the mechanical response of the cobalt superalloy specimens is directly related to the effects of the titanium contents, strain rate and temperature on the evolution of the microstructure. It can be observed that the strengthening effect in cobalt-based superalloys is a result primarily of dislocation multiplication. The dislocation density increases with increasing strain rate, but decreases with increasing temperature.

Comparison of Two Fixation Methods of Oblique Lesser Metatarsal Osteotomies: A Biomechanical Study

1995 ◽  
Vol 16 (7) ◽  
pp. 437-439 ◽  
Author(s):  
Mark P. Slovenkai ◽  
Daniel Linehan ◽  
Linda McGrady ◽  
Tae-Hong Lim ◽  
Gerald F. Harris ◽  
...  
Keyword(s):  
Internal Fixation ◽  
Screw Fixation ◽  
Material Testing ◽  
Biomechanical Study ◽  
Testing System ◽  
Human Cadaver ◽  
Kirschner Wires ◽  
Fixation Methods ◽  
Single Screw ◽  
Fresh Frozen

Two methods of internal fixation of oblique lesser metatarsal osteotomies were compared biomechanically using fresh-frozen human cadaver bones. Osteotomies were made obliquely through the metatarsal shafts and fixed with either crossed Kirschner wires or a single AO screw using the lag technique. The specimens were then fixed at their proximal end and loaded to failure using an axial torsion material testing system (MTS, Minneapolis, MN). Load displacement curves were obtained and the stiffness of the constructs was determined. Single-screw fixation was found to be significantly stiffer than the crossed wire configuration ( P < .01). Single-screw fixation resulted in a stiffness of 211.2 ± 111.7 N/cm (mean ± SD), while stiffness of the crossed wire configuration averaged 56.9 ± 25.1 N/cm.

1106 Tensile Tests on Steels and Aluminum alloys in a Wide Range of Strain Rates by High Speed Material Testing System with Sensing Block

2000 ◽  
Vol 2000.75 (0) ◽  
pp. _11-11_-_11-12_
Author(s):  
Takeshige MACHIGAKI ◽  
Yoshitaka ASHIDA ◽  
Koji MIMURA ◽  
Tsutomu UMEDA ◽  
Shinji TANIMURA
Keyword(s):  
Aluminum Alloys ◽  
High Speed ◽  
Tensile Tests ◽  
Material Testing ◽  
Testing System ◽  
Strain Rates ◽  
Wide Range

Ultimate Strength and Plasticity of Magnesium Alloy under Different Temperatures and Strain Rates

2011 ◽  
Vol 686 ◽  
pp. 225-229
Author(s):  
Bin Chen ◽  
Da Gang Yin ◽  
Quan Yuan ◽  
Ji Luo ◽  
Ding Fei Zhang ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Ultimate Strength ◽  
Fracture Stress ◽  
Tensile Tests ◽  
Material Testing ◽  
Testing System ◽  
Strain Rates ◽  
Az61 Magnesium Alloy ◽  
Different Temperatures ◽  
Strength And Plasticity

A series of tensile tests of AZ61 magnesium alloy were conducted using Gleeble-1500 thermal-mechanical material testing system to learn the effect of the test temperatures and strain rates on the mechanical properties of the alloy. It is indicated that the higher the temperature, the lower the ultimate strength and fracture stress, and the larger the plasticity. It is also revealed that the larger the strain rate is, the higher the ultimate strength of the specimens will be, and the larger the plasticity of the specimens will be. The failure mechanism of the material under high temperature was also analyzed based on the fracture observation. It shows that the high temperatures will induce microvoids or microflaws in the material.

Design of NRL66.4: An Electro-Hydraulic 6-DoF Parallel Robotic Multiaxial Material Testing System

2019 ◽  
Author(s):  
John G. Michopoulos ◽  
Athanasios P. Iliopoulos ◽  
John C. Steuben ◽  
Benjamin D. Graber
Keyword(s):  
Degrees Of Freedom ◽  
Material Testing ◽  
Multiaxial Fatigue ◽  
Current Status ◽  
Testing System ◽  
Damage Propagation ◽  
Propagation Modeling ◽  
Multiaxial Testing ◽  
Reaction Forces ◽  
6 Degrees Of Freedom

Abstract Contemporary material testing applications such as high throughput material testing under realistic conditions, emulation of in-service loading conditions for the qualification of additively manufactured parts, material failure and damage propagation modeling validation and material constitutive characterization, are all underscoring the demand for an automated multiaxial testing capability. In order to address these needs, the present work introduces the initial progress of the design and prototyping of a 6 degrees of freedom (6-DoF) robotic system to be used as such a testing infrastructure. This system is designed to be capable of enforcing 6-DoF kinematic or force controlled boundary conditions on deformable material specimens, while at the same time measuring both the imposed kinematics and the corresponding reaction forces in a fully automated manner. Furthermore, as an extension to our previously prototyped systems, the system proposed here is designed to apply both quasi-static loading but also cyclic loading for enabling multiaxial fatigue studies. In addition to the architecture, the design and current status of its implementation for the most critical sub-systems is presented.

Miniature Autoclave and Double Bellows Loading Device for Material Testing in Future Reactor Concept Conditions—Case Supercritical Water

2017 ◽  
Vol 4 (1) ◽  
Author(s):  
Sami Penttilä ◽  
Pekka Moilanen ◽  
Wade Karlsen ◽  
Aki Toivonen
Keyword(s):  
Supercritical Water ◽  
Deformation Behavior ◽  
Material Testing ◽  
Light Water Reactor ◽  
Harsh Environments ◽  
Testing System ◽  
Testing Device ◽  
Loading Device ◽  
Temperature And Pressure

The presented work consists of a test setup study of a new pneumatic material testing device based on double bellows (DBs) loading device and with miniature autoclaves enabling applications at temperature and pressure up to 650 °C and 35 MPa, respectively. It has been demonstrated that it is technically feasible to carry out well defined and controlled material testing in the supercritical water (SCW) environment using this testing system. By using this type of system, it makes possible to investigate the intrinsic role of the applied stress on the deformation behavior of material in light water reactor (LWR) conditions and also in other harsh environments like SCW conditions. In addition, the compactness and versatility of the setup makes this system particularly attractive for deployment in a hot-cell for testing of irradiated materials.

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