Clinical evaluation of a prosthetic suspension system: Looped silicone liner

2016 ◽  
Vol 41 (5) ◽  
pp. 476-483 ◽  
Author(s):  
Noor Azuan Abu Osman ◽  
Hossein Gholizadeh ◽  
Arezoo Eshraghi ◽  
Wan Abu Bakar Wan Abas

Objectives: This study aimed to evaluate and compare a newly designed suspension system with a common suspension in the market. Study design: Prospective study. Methods: Looped liners with hook fastener and Iceross Dermo Liner with pin/lock system were mechanically tested using a tensile testing machine in terms of system safety. A total of 10 transtibial amputees participated in this study and were asked to use these two different suspension systems. The pistoning was measured between the liner and socket through a photographic method. Three static axial loading conditions were implemented, namely, 30, 60, and 90 N. Furthermore, subjective feedback was obtained. Results: Tensile test results showed that both systems could safely tolerate the load applied to the prosthesis during ambulation. Clinical evaluation confirmed extremely low pistoning in both systems (i.e. less than 0.4 cm after adding 90 N traction load to the prosthesis). Subjective feedback also showed satisfaction with both systems. However, less traction at the end of the residual limb was reported while looped liner was used. Conclusion: The looped liner with hook fastener is safe and a good alternative for individuals with transtibial amputation as this system could solve some problems with the current systems. Clinical relevance The looped liner and hook fastener were shown to be good alternative suspension for people with lower limb amputation especially those who have difficulty to use and align the pin/lock systems. This system could safely tolerate centrifugal forces applied to the prosthesis during normal and fast walking.

2021 ◽  
Vol 2 (1) ◽  
pp. 17-20
Author(s):  
Misbachuddin

 This study aimed to decide how to design a kart chassis and the strength of the welded joints. In this design, the chassis frame is made of tubular profile steel, which is designed to withstand most of the loads in a vehicle. The chassis was designed using a computer application, namely Auto CAD 2007. Assembly using carbon steel pipes connected using SMAW welding with E6013 RB 2.6 mm welding wire with a current of 75 A, 1G place. The test is carried out with a tensile testing machine. The material is pulled past the most stretch elasticity limit until finally, the specimen reaches the limit (breaks). The tensile test takes about 3-5 minutes with a load of 10-20N. The test results show the average tensile strength of the iron pipe is 0.512 Mpa.


2019 ◽  
Vol 889 ◽  
pp. 51-57
Author(s):  
Gia Hai Vuong ◽  
Nguyen Thi Hong Minh ◽  
Nguyen Duc Toan

This paper presents the experimental test results on mechanical properties of steel plate grade SS400 at elevated temperatures. The steel is often used as structural steel due to its weldability and machinability. The steel plates were heated by a high frequency heating system to reach specific temperatures before being tested on a tensile testing machine. Five different temperature conditions were used, namely room temperature, 100°C, 300°C, 500°C and 600°C. The data of mechanical properties measured for SS400 steel plates at various temperature conditions were recorded and analysed. The research showed that when the temperature is increased, the force in tensile test is decreased while the strain is increased. The observation and the data were then used to setup the stress – strain – temperature relation for formability study of SS400 steel plates. The same method can be used to establish the mechanical properties at elevated temperatures.


2021 ◽  
Vol 65 (1) ◽  
pp. 105-107
Author(s):  
Yaroslav Kosmatskiy ◽  
Nikolai Fokin ◽  
Kseniya Yakovleva ◽  
Vladislav Nikolenko ◽  
Boris Barichko ◽  
...  

The article presents the results of a research of the dependence of the mechanical properties of the CrNi60WTi alloy on the degree of cold deformation. As part of the study, five samples were taken from a pipe with an outer diameter of 89.0 mm and a wall thickness of 11.0 mm. The samples were cold-deformed to varying degrees and static tensile tests were performed on an SSI MTSInsight tensile testing machine. Based on the test results, the dependences of the mechanical properties on the degree of cold deformation were calculated.


2021 ◽  
Vol 2 (2) ◽  
pp. 274-288
Author(s):  
Md Shahnewaz Bhuiyan ◽  
Muhommad Azizur Rahman ◽  
Md Shahriar Farabi ◽  
Md Mahedi Hasan

In the present work, an investigation on the surface topography and geometry variation of bagasse fibers was correlated with their mechanical properties via image analysis. The fibers were tested under a universal tensile testing machine and the diameter of the fibers was calculated using images obtained in a digital microscope. Furthermore, surface characterization and quantification were also performed using images obtained via SEM. The results showed that the surface roughness of alkali-treated bagasse fiber increased compared to that of the untreated one. Moreover, it was observed that the diameter variation of bagasse fiber along its length and among different fibers is not only variable but also unpredictable. The tensile test results revealed that bagasse fibers showed lower stress at a rupture with considerable scatter. It can be inferred that the synergistic effect of thick bagasse fiber, bagasse fiber diameter variations along its length and among fibers, and the fiber fracture mechanism establishes a local condition for fracture and resulted in such variations in tensile properties. Finally, the results clearly showed that the two-parameter Weibull fit the experimental data fairly well (R2=0.97). The Weibull modulus (m) was found to be 1.7, indicating that the strength distribution is high.


10.14311/468 ◽  
2003 ◽  
Vol 43 (5) ◽  
Author(s):  
J. Titlestad ◽  
T. Fairlie-Clarke ◽  
M. Davie ◽  
A. Whittaker ◽  
S. Grant

A significant distinction between competitive mountain bikes is whether they have a suspension system. Research studies indicate that a suspension system gives advantages, but it is difficult to quantify the benefits because they depend on so many variables, including the physiology and psychology of the cyclist, the roughness of the track and the design of the suspension system. A laboratory based test rig has been built that allows the number of variables in the system to be reduced and test conditions to be controlled. The test rig simulates regular impacts of the rear wheel with bumps in a rolling road. The physiological variables of oxygen consumption and heart rate were measured, together with speeds and forces at various points in the system. Physiological and mechanical test results both confirm a significant benefit in using a suspension system on the simulated rough track, with oxygen consumption reduced by around 30 % and power transmitted through the pedals reduced by 30 % to 60 %.


2011 ◽  
Vol 689 ◽  
pp. 361-366 ◽  
Author(s):  
Ping Lu ◽  
Jing Zhang ◽  
Wei Bo Huang ◽  
Xu Dong Liu

Two types of polyurea coatings based on polyaspartic esters (PAE) (PAE-F1 and PAE-F2) were exposed in salt fog environments and outdoor for different time periods. The aging behaviors of two types of coatings were evaluated by using electronic tensile testing machine, glossmeter and Fourier transform infrared spectroscopy (FTIR). The results showed that the salt fog had a significant effect on the gloss loss, hydrogen-bonded urea carbonyl in PAE-F1 and PAE-F2 were 77.1% and 74.9% respectively by the results obtained from FTIR analysis. The index of gloss loss, strength change rate and elongation at break change rate of PAE-F1 and PAE-F2 coatings kept well exposed in outdoor and salt fog environment after 350 days. All test results indicated that PAE coating has excellent aging resistance; PAE-F1 with higher degree of hydrogen bond was more orderly structural and better aging resistant than PAE-F2 coating.


2014 ◽  
Vol 875-877 ◽  
pp. 534-541 ◽  
Author(s):  
Chawalit Thinvongpituk ◽  
Nirut Onsalung

In this paper, the experimental investigation of polyurethane (PU) foam-filled into circular aluminum tubes subjected to axial crushing was presented. The purpose of this study is to improve the energy absorption of aluminium tube under axial quasi-static load. The aluminium tube was made from the AA6063-T5 aluminium alloy tubes. Each tube was filled with polyurethane foam. The density of foam was varied from 100, 150 and 200 kg/mP3P including with empty tube. The range of diameter/thickness (D/t) ratio of tube was varied from 15-55. The specimen were tested by quasi-static axial load with crush speed of 50 mm/min using the 2,000 kN universal testing machine. The load-displacement curves while testing were recorded for calculation. The mode of collapse of each specimen was analyzed concerning on foam density and the influence of D/t ratio. The results revealed that the tube with foam-filled provided significantly increment of the energy absorption than that of the empty tube. While the density of foam and D/t ratios increase, the tendency of collapse mode is transformed from asymmetric mode to concertina mode.


Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2042
Author(s):  
Wojciech Kacalak ◽  
Igor Maciejewski ◽  
Dariusz Lipiński ◽  
Błażej Bałasz

A simulation model and the results of experimental tests of a vibration generator in applications for the hot-dip galvanizing process are presented. The parameters of the work of the asynchronous motor forcing the system vibrations were determined, as well as the degree of unbalance enabling the vibrations of galvanized elements weighing up to 500 kg to be forced. Simulation and experimental tests of the designed and then constructed vibration generator were carried out at different intensities of the unbalanced rotating mass of the motor. Based on the obtained test results, the generator operating conditions were determined at which the highest values of the amplitude of vibrations transmitted through the suspension system to the galvanized elements were obtained.


Author(s):  
A. Olivier ◽  
J. Wannenburg ◽  
R.D. Gottschalk ◽  
M.J. Van der Linde ◽  
H.T. Groeneveld

A shoe was designed to combine the advantages of a reverse shoe and an adjustable heart bar shoe in the treatment of chronic laminitis. This reverse even frog pressure (REFP) shoe applies pressure uniformly over a large area of the frog solar surface. Pressure is applied vertically upward parallel to the solar surface of the frog and can be increased or decreased as required. Five clinically healthy horses were humanely euthanased and their dismem-bered forelimbs used in an in vitro study. Frog pressure was measured by strain gauges applied to the ground surface of the carrying tab portion of the shoe. A linear variable distance transducer (LVDT) was inserted into a hole drilled in the dorsal hoof wall. The LVDT measured movement of the third phalanx (P3) in a dorsopalmar plane relative to the dorsal hoof wall. The vertical component of hoof wall compression was measured by means of unidirectional strain gauges attached to the toe, quarter and heel of the medial hoof wall of each specimen. The entire limb was mounted vertically in a tensile testing machine and submitted to vertical downward compressive forces of 0 to 2500 Nat a rate of 5 cm/minute. The effects of increasing frog pressure on hoof wall weight-bearing and third phalanx movement within the hoof were determined. Each specimen was tested with the shoe under the following conditions: zero frog pressure; frog pressure used to treat clinical cases of chronic laminitis (7 N-cm); frog pressure clinically painful to the horse as determined prior to euthanasia; frog pressure just alleviating this pain. The specimens were also tested after shoe removal. Total weight-bearing on the hoof wall at zero frog pressure was used as the basis for comparison. Pain-causing and pain-alleviating frog pressures decreased total weight-bearing on the hoof wall (P < 0.05). Frog pressure of 7 N-cm had no statistically significant effect on hoof wall weight-bearing although there was a trend for it to decrease as load increased. Before loading, the pain-causing and pain-alleviating frog pressures resulted in a palmar movement of P3 relative to the dorsal hoof wall compared to the position of P3 at zero frog pressure (P < 0.05). This difference remained statistically significant up to 1300 Nload. At higher loads, the position of P3 did not differ significantly for the different frog pressures applied. It is concluded that increased frog pressure using the REFP shoe decreases total hoof wall weight-bearing and causes palmar movement of P3 at low weight-bearing loads. Without a shoe the toe and quarter hoof wall compression remained more constant and less in magnitude, than with a shoe.


1978 ◽  
Vol 14 (3) ◽  
pp. 269-272 ◽  
Author(s):  
J. F. M. Fennell

SUMMARYThe use of a durometer to assess hardness of onion bulbs is described, and compared with the use of a tensile testing machine. Results from the two tests were closely correlated, and significant varietal differences were detected in bulb hardness by both machines. The durometer is of particular value because of the simplicity and non-destructive nature of the test procedure.


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