scholarly journals Evaluation of Contact Pressure in Bending under Tension Test by a Pressure Sensitive Film

2016 ◽  
Vol 06 (04) ◽  
pp. 201-214 ◽  
Author(s):  
Luis Fernando Folle ◽  
Lirio Schaeffer
Keyword(s):  
Contact Pressure ◽  
Tension Test ◽  
Pressure Sensitive ◽  
Sensitive Film ◽  
Pressure Sensitive Film ◽  
Bending Under Tension

scholarly journals Evaluation of laparoscopic forceps jaw contact pressure and distribution using pressure sensitive film

2019 ◽  
Vol 24 (sup2) ◽  
pp. 105-116 ◽  
Author(s):  
Rui Zhu ◽  
Maxime Maréchal ◽  
Ikuo Yamamoto ◽  
Murray John Lawn ◽  
Takeshi Nagayasu ◽  
...  
Keyword(s):  
Contact Pressure ◽  
Pressure Sensitive ◽  
Sensitive Film ◽  
Pressure Sensitive Film

Measurement of Contact Pressure in Metal Forming by Pressure Sensitive Film

1984 ◽  
Vol 106 (2) ◽  
pp. 127-131 ◽  
Author(s):  
K. Mori ◽  
K. Osakada ◽  
M. Fukuda
Keyword(s):  
Contact Pressure ◽  
Metal Forming ◽  
Maximum Pressure ◽  
Rigid Plastic ◽  
Workpiece Material ◽  
Simple Method ◽  
Pressure Sensitive ◽  
Sensitive Film ◽  
Color Density ◽  
Pressure Sensitive Film

A simple method is presented for measuring the distribution of tool contact pressure in metal forming by using a pressure sensitive film which detects the contact pressure from the change in color density. In the method, a sufficiently hard sheet metal compared to the workpiece is inserted between the workpiece and the pressure sensitive film in order to eliminate the influence of frictional shear stress at the tool-workpiece interface on the measured result. Since the maximum pressure which can be determined by the film is 150MPa, lead is used as a workpiece material. Distributions of tool contact pressure are measured in upsetting of cylindrical billets, in free forging of plates of various shapes, and also in backward extrusion of a can. The measured distributions agree well with those computed by the rigid-plastic finite element method.

Customized surface-guided knee implant: Contact analysis and experimental test

2017 ◽  
Vol 232 (1) ◽  
pp. 90-100 ◽  
Author(s):  
Ida Khosravipour ◽  
Shabnam Pejhan ◽  
Yunhua Luo ◽  
Urs P Wyss
Keyword(s):  
Molecular Weight ◽  
Finite Element ◽  
High Molecular Weight ◽  
Contact Pressure ◽  
Element Analysis ◽  
Pressure Sensitive ◽  
Sensitive Film ◽  
Pressure Sensitive Film ◽  
Total Knee ◽  
Ultra High Molecular Weight

Contact pressure and stresses on the articulating surface of the tibial component of a total knee replacement are directly related to the joint contact forces and the contact area. These stresses can result in wear and fatigue damage of the ultra-high-molecular-weight polyethylene. Therefore, conducting stress analysis on a newly designed surface-guided knee implant is necessary to evaluate the design with respect to the polyethylene wear. Finite element modeling is used to analyze the design’s performance in level walking, stair ascending and squatting. Two different constitutive material models have been used for the tibia component to evaluate the effect of material properties on the stress distribution. The contact pressure results of the finite element analysis are compared with the results of contact pressure using pressure-sensitive film tests. In both analyses, the average contact pressure remains below the material limits of ultra-high-molecular-weight polyethylene insert. The peak von Mises stresses in 90° of flexion and 120° of flexion (squatting) are 16.28 and 29.55 MPa, respectively. All the peak stresses are less than the fatigue failure limit of ultra-high-molecular-weight polyethylene which is 32 MPa. The average contact pressure during 90° and 120° of flexion in squatting are 5.51 and 5.46 MPa according to finite element analysis and 5.67 and 8.14 MPa according to pressure-sensitive film experiment. Surface-guided knee implants are aimed to resolve the limitations in activities of daily living after total knee replacement by providing close to normal kinematics. The proposed knee implant model provides patterns of motion much closer to the natural target, especially as the knee flexes to higher degrees during squatting.

Contact Pressures at Osteochondral Donor Sites in the Knee

1998 ◽  
Vol 26 (4) ◽  
pp. 491-494 ◽  
Author(s):  
Peter T. Simonian ◽  
Patrick S. Sussmann ◽  
Thomas L. Wickiewicz ◽  
George A. Paletta ◽  
Russell F. Warren
Keyword(s):  
Contact Pressure ◽  
Donor Site ◽  
Knee Motion ◽  
Pressure Sensitive ◽  
Sensitive Film ◽  
Color Density ◽  
Pressure Sensitive Film ◽  
The Difference ◽  
Different Color ◽  
Contact Pressures

The purposes of this study were to determine whether any of the commonly recommended osteochondral donor sites are nonarticulating throughout a functional range of knee motion, and to determine the differential contact pressures for these sites. Ten commonly recommended sites for osteochondral harvest were evaluated with pressure-sensitive film through a functional range of motion with a model that simulated nonweightbearing resistive extension of the knee. All 10 donor sites demonstrated a significant contact pressure through 0° to 110° of knee motion. The different color density measurements between donor sites were also significant. Although donor sites 1, 2, 9, and 10 demonstrated significantly less contact pressure than the sites with the greatest contact pressure, the difference in mean pressures was small. No osteochondral donor site tested was free from contact pressure. It is currently unknown whether articular contact at these osteochondral donor sites will lead to degenerative changes or any other problems.

Mechanical Responses of the Rabbit Patello-Femoral Joint to Blunt Impact

1995 ◽  
Vol 117 (4) ◽  
pp. 402-408 ◽  
Author(s):  
R. C. Haut ◽  
T. M. Ide ◽  
C. E. De Camp
Keyword(s):  
Contact Pressure ◽  
Cartilage Damage ◽  
Damage Zone ◽  
Small Animal ◽  
Mechanical Responses ◽  
Pressure Sensitive ◽  
Sensitive Film ◽  
Patellar Cartilage ◽  
Pressure Sensitive Film ◽  
Contact Pressures

Various studies suggest impact trauma may initially soften cartilage, damage subchondral bone, or a combination thereof. The initial damages are commonly thought due to excessive contact pressures generated on cartilage and the underlying bone. The objective of this research was to develop a small animal model for studying post-traumatic OA and to correlate contact pressures with tissue damage. Blunt insult was graded by dropping a rigid mass onto the hyperflexed hind limb of rabbits. Contact pressure in the patello-femoral joint was measured with pressure sensitive film. One, 3, 6, and 14 days later the animals were euthanized. Damage to cartilage and the underlying bone was assessed visually and in microscopic sections. Indentation experiments were performed on the patellar cartilage with a rigid, flat probe. Contact pressures were nonuniform over the articular surfaces and a high frequency of surface fissures were generated on the lateral facet in severe insults. The appearance of surface fissures correlated better with the magnitude of contact pressure gradients in the damage zone than the magnitude of contact pressures on the facet, per se. Blunt trauma causing surface fissures resulted in a measurable degree of softening in the patellar cartilage, especially close to the defects. Surgical intervention of the joint to insert pressure sensitive film, however, also resulted in significant softening of the cartilage.

The Use of Contact Biomechanics to Study the Intact, Proximal Row Carpectomy and Scaphoid Excision, Four Bone Fusion Wrist

2020 ◽  
Vol 16 (3) ◽  
pp. 189-193
Author(s):  
David H. Wei ◽  
Peter Tang
Keyword(s):  
Proximal Row Carpectomy ◽  
Scapholunate Ligament ◽  
Bone Fusion ◽  
Pressure Sensitive ◽  
Sensitive Film ◽  
Radiocarpal Joint ◽  
Pressure Sensitive Film ◽  
Number Of Authors

The study of contact biomechanics of the wrist is a challenge. This is partly due to the relatively small size of the joint as well as the lack of space in the radiocarpal joint which makes the delivery of investigative materials such as pressure sensitive film without causing artifact, difficult. Fortunately, a number of authors have studied the intact wrist, the scapholunate ligament injured wrist, the proximal row carpectomy and the scaphoid excision, four bone fusion. Despite some contrasting findings, there are some general concepts that we understand about wrist mechanics.

A Technique for Measuring Absolute Toe Pressures: Evaluation of Pressure-Sensitive Film Techniques

Foot & Ankle ◽  
1992 ◽  
Vol 13 (4) ◽  
pp. 220-223 ◽  
Author(s):  
Alan S. Tuckman ◽  
Frederick W. Werner ◽  
Maria D. Fortino ◽  
Joseph A. Spadaro
Keyword(s):  
Soft Tissues ◽  
Flat Surface ◽  
Imaging System ◽  
Accurate Method ◽  
Total Force ◽  
Confined Space ◽  
Pressure Sensitive ◽  
Sensitive Film ◽  
Pressure Sensitive Film ◽  
Deforming Forces

Although a number of pathologies of the forefoot in ballet dancers on pointe have been described, pressures and deforming forces have not been adequately measured. To evaluate the possible use of pressure-sensitive film (PSF) in measuring the pressures on the external soft tissues in such a confined space as the dancer's toe shoe, it was tested and calibrated with 20 cadaver toes. Each cadaver toe was internally stabilized and loaded longitudinally against PSF on a flat surface. The resultant films were analyzed with a video imaging system and the pressures and total forces were determined. Results showed that the linearity of the PSF to pressure had a regression value of 0.98. By using two sensitivity ranges of films, the total force measured by the PSF was found to be within 10% of the known applied force on each toe. The PSF, therefore, may very well be a useful and accurate method of measuring external soft tissue pressures on the forefoot.

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