Custom Contoured Cushion: A Finite Element Analysis

2012 ◽  
Vol 433-440 ◽  
pp. 86-93
Author(s):  
Se Kou Singare ◽  
Zhou Yan Zhong ◽  
Guang Hui Xu ◽  
Jiang Jun Zhou
Keyword(s):  
Pressure Distribution ◽  
Laser Scanner ◽  
Pressure Sore ◽  
Healthy Male Subject ◽  
Assessment System ◽  
Distribution Data ◽  
Mathematics Model ◽  
Element Analysis ◽  
Custom Made ◽  
System Data

A good chair cushion not only provides comfort but also control the posture and to reduce the risk of pressure sore occurred. The purpose of this study was to evaluate the mechanical interaction between the cushion and user of wheelchair. The buttock model geometric, individual data’s of healthy male subject were acquired by 3D reconstruction form laser scanner, while the custom made cushion design based on the Tekscan Clinseat pressure assessment system data. A standard clinical experiment protocol for the collection of interface pressure distribution was developed. The pressure distribution data of buttocks-cushion interface was collected when the subject sat on an initial cushion. According to the pressure distribution data and parameters of cushion material that was acquired in the material test; an individual mathematics model was built and then transferred into CAD software to create the CAD model of the cushion deflection geometry.

scholarly journals Pressure sensing and control of an aircraft passenger seat

2021 ◽  
Author(s):  
Gabriel H. Campos
Keyword(s):  
Control System ◽  
Pressure Distribution ◽  
High Surface ◽  
Distribution Data ◽  
Pressure Sensing ◽  
Surface Change ◽  
Passenger Seat ◽  
Seat Comfort ◽  
And Control ◽  
High Surface Pressure

The premise of this work is to address aircraft seat comfort. This thesis presents the development of an automatic morphing backrest used to reduce pressure experienced by the passenger from the seat. Uncomfortable, high surface pressure zones on the backrest can be alleviated by decentralizing the occupant’s weight. The improved pressure distribution is intended to decrease discomfort during flight while taking different comfort/discomfort models into consideration. Pressure distribution data from the embedded sensor mat is used to compute the seat’s cushion deflection and corresponding backrest contour caused by the passenger’s weight. The surfaces of interest - the passenger’s back and the seat, are modelled and discretized. The discretized surface contact pressure is integrated into the hyperelastic contact model to determine the loading profile. From this, the current pressure distribution and the cushion’s surface change are computed and used in the control system to create the corresponding actuation of the surface.

INFLUENCE OF CUSTOMIZED FOOT ORTHOTICS ON GAIT BALANCE FOR PELVIC ASYMMETRY PATIENTS

2019 ◽  
Vol 19 (05) ◽  
pp. 1950039
Author(s):  
JI-YONG JUNG ◽  
JUNG-JA KIM
Keyword(s):  
Pressure Distribution ◽  
Plantar Pressure ◽  
Gait Pattern ◽  
Biomechanical Stress ◽  
Lower Extremity Muscle ◽  
Plantar Pressure Distribution ◽  
Human Movements ◽  
Custom Made ◽  
Postural Imbalance ◽  
Electromyography Signals

Gait is one of the most common and important factor of human movements in daily life. Pelvis is closely connected with the gait due to it allows maintain stable posture by supporting the spine and lower extremities against the gravity. Therefore, pelvic asymmetry, which is caused by biomechanical stress and muscle imbalance, has been associated with postural imbalance and abnormal walking pattern. The purpose of this study was to manufacture customized foot orthotics for improving gait balance and evaluate the effectiveness of customized foot orthotics during walking by measuring lower extremity muscle activity and plantar pressure distribution. All subjects with pelvic asymmetry were asked to walk on a treadmill under three conditions: walking without foot orthotics, walking with customized foot orthotics and walking with non-customized foot orthotics. Root mean square (RMS) value of the electromyography signals, force and peak pressure of the plantar pressure distribution was analyzed based on the gait cycle. The results showed that excessive tension of the muscles and high pressure of the foot that was induced by pelvic asymmetry were more reduced when walking with custom-made foot orthotics than walking without foot orthotics and walking with non-customized foot orthotics. This paper suggest that custom-made orthotics for patients with pelvic asymmetry could be helpful to relieve the excessive loading of the foot and maintain balanced gait pattern.

scholarly journals An Analysis Tool for the Installation of Submarine Cables in an S-Lay Configuration Including “In and Out of Water” Cable Segments

2020 ◽  
Vol 8 (1) ◽  
pp. 48 ◽  
Author(s):  
Vasileios A. Mamatsopoulos ◽  
Constantine Michailides ◽  
Efstathios E. Theotokoglou
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Design Criterion ◽  
Limiting Factors ◽  
Radius Of Curvature ◽  
Analysis Tool ◽  
Analysis Software ◽  
Element Analysis ◽  
Analysis And Design ◽  
Custom Made

Today, the offshore oil and gas and wind power industry is a heavily regulated segment, and current standards have established restrictions which yield a very limited weather window for submarine cable installations due to experience with cable failure in bad weather. There are two main limiting factors in current practice during cable installation of an S-lay configuration: the design criterion for the minimum allowable radius of curvature in the touch down point and the avoidance of axial compression in the touch down zone. Accurate assessment of the cable integrity during offshore installation has drawn great attention and is related to the existing available analysis and design tools. The main purpose of this paper is to develop and propose a quick and easy custom-made analysis tool, which is able to export similar results as sophisticated finite element analysis software. The developed tool utilizes analytical equations of a catenary-type submarine structure extended to account for varying cross-sections with different weights and/or stiffnesses, as is the real practice. A comparative study is presented in this paper to evaluate the significance for the modeling of the “out of water” cable segment required for accurate safety factor quantification during a laying operation. The efficiency and accuracy of the proposed tool are proven through a validation study comparing the results and the computational effort and time with commercial finite element analysis software. The analysis error in the case of not modeling the “out of water” cable part is significant, especially in shallow water areas, which proves the importance of using the proposed analysis tool.

Analysis on the Contact Pressure Distribution of Chemical Mechanical Polishing by the Bionic Polishing Pad with Phyllotactic Pattern

2011 ◽  
Vol 215 ◽  
pp. 217-222 ◽  
Author(s):  
Y.S. Lv ◽  
Nan Li ◽  
Jun Wang ◽  
Tian Zhang ◽  
Min Duan ◽  
...  
Keyword(s):  
Pressure Distribution ◽  
Contact Pressure ◽  
Chemical Mechanical Polishing ◽  
Mechanical Polishing ◽  
Wafer Surface ◽  
Boundary Edge ◽  
Contact Pressure Distribution ◽  
Element Analysis ◽  
Pressure Distributions ◽  
Polishing Pad

In order to make the contact pressure distribution of polishing wafer surface more uniform during chemical mechanical polishing (CMP), a kind of the bionic polishing pad with sunflower seed pattern has been designed based on phyllotaxis theory, and the contact model and boundary condition of CMP have been established. Using finite element analysis, the contact pressure distributions between the polishing pad and wafer have been obtained when polishing silicon wafer and the effects of the phyllotactic parameter of polishing pad on the contact pressure distribution are found. The results show that the uniformity of the contact pressure distribution can be improved and the singularity of the contact pressure in the boundary edge of polished wafer can be decreased when the reasonable phyllotactic parameters are selected.

Study on New Bimetal Floating Seal of High Speed Roller Bit Bearing

2011 ◽  
Vol 233-235 ◽  
pp. 2158-2165
Author(s):  
Zhi Qiang Huang ◽  
Yi Zhou ◽  
Qin Li ◽  
Wei Li ◽  
Zhen Chen ◽  
...  
Keyword(s):  
Pressure Distribution ◽  
Compression Ratio ◽  
High Speed ◽  
Surface Engineering ◽  
Material Surface ◽  
Metal Ring ◽  
Element Analysis ◽  
Premature Failure ◽  
Rubber Ring ◽  
Sealing Pressure

ANSYS software has been used for high speed rock bit bimetal floating seal finite element analysis, as a result, overlarge pressure of bearing seal, unreasonable pressure distribution and overlarge compression ratio of rubber ring, are main reasons for premature failure of the bearing seal. For this, the optimal design and analysis of bearing seal structure is carried out in this paper. The results showed that: the new structure of the bearing seal has effectively reduced the compression ratio of rubber ring, improved the sealing pressure distribution based on reliable sealing conditions and further reduced the sealing pressure peak. The design of dynamic metal ring flywheel lubrication groove and the application of static metal ring antifriction material surface engineering technology have obviously reduced surface friction factor and wear of metal ring, greatly improved the effectiveness and life of the seal, and further extended the bit’s life.

Three-Dimensional Finite Element Analysis of Custom-Made Ceramic Dowel Made Using CAD/CAM Technology

2012 ◽  
Vol 21 (6) ◽  
pp. 440-450 ◽  
Author(s):  
Thamer Yousif Marghalani ◽  
Mohamed Tharwat Hamed ◽  
Mohamed Abdelmageed Awad ◽  
Ghada Hussein Naguib ◽  
Ahmed Fouad Elragi
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Three Dimensional ◽  
Element Analysis ◽  
Custom Made ◽  
Dimensional Finite Element ◽  
Cad Cam ◽  
Three Dimensional Finite Element

Changes in Plantar Foot Pressure with In-Shoe Varus or Valgus Wedging

2004 ◽  
Vol 94 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Bart Van Gheluwe ◽  
Howard J. Dananberg
Keyword(s):  
Pressure Distribution ◽  
Loading Rate ◽  
Peak Pressure ◽  
Center Of Pressure ◽  
Scientific Evidence ◽  
Peak Load ◽  
Foot Orthoses ◽  
Foot Pressure ◽  
Custom Made

Varus and valgus wedging are commonly used by podiatric physicians in therapy with custom-made foot orthoses. This study aimed to provide scientific evidence of the effects on plantar foot pressure of applying in-shoe forefoot or rearfoot wedging. The plantar foot pressure distribution of 23 subjects walking on a treadmill was recorded using a pressure insole system for seven different wedging conditions, ranging from 3° valgus to 6° varus for the forefoot and from 4° valgus to 8° varus for the rearfoot. The results demonstrate that increasing varus wedging magnifies peak pressure and maximal loading rate at the medial forefoot and rearfoot, whereas increasing valgus wedging magnifies peak pressure and maximal loading rate at the lateral forefoot and rearfoot. As expected, the location of the center of pressure shifts medially with varus wedging and laterally with valgus wedging. However, these shifts are less significant than those in peak load and maximal loading rate. Timing variables such as interval from initial impact to peak load do not seem to be affected by forefoot or rearfoot wedging. Finally, rearfoot wedging does not significantly influence pressure variables of the forefoot; similarly, rearfoot pressure remains unaffected by forefoot wedging. (J Am Podiatr Med Assoc 94(1): 1-11, 2004)

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