Design and Strength Analysis of the Wheelchair Switching Mechanism

2014 ◽  
Vol 494-495 ◽  
pp. 337-340 ◽  
Author(s):  
Yu Wen Li ◽  
Jian Kang Wei ◽  
Jin Zhang

Based on studying the existing electric wheelchairs for disabled are not well adapted to a variety of road conditions, broken through the structure of traditional wheelchairs, a design proposal that can make electric wheelchair achieve the function of climbing stairs and walking was putted forward and a novel mechanism was designed. The mechanism can make the crawler chassis and the wheels of wheelchair switch when needed, and make the wheelchair travel freely and flexible on the ground or on the stairs. The finite element model of the mechanism was built, and the strength analysis was carried out. The strength analysis provide the theoretical basis for the prototype manufacture.

2013 ◽  
Vol 303-306 ◽  
pp. 2871-2875
Author(s):  
Jian Yong Li ◽  
Chao Zhang ◽  
Hong Lu Su ◽  
Fang Yi Li ◽  
Shun Shun Qin ◽  
...  

Focusing on the dredging problem in Yellow River irrigation district, the whip-impact sediment dredging technology is put forward in the Xingjiadu Irrigation District. The finite element model of dredging process is built and the flow characteristic and behavior under design condition is studied, which can provide a theoretical basis for the feasibility of the whip-impact sediment dredging technology. Also, it can provide effective measures for the improvement of sediment dredging effects and whip-impact equipments.


2012 ◽  
Vol 252 ◽  
pp. 172-175
Author(s):  
Zhi Ping Guo ◽  
Wei Guo ◽  
Yan Fei Wang ◽  
Guan Fu Li ◽  
Yan Zheng Lu

Cone is one part of a packer. To understand the seal effectiveness of the packer, mechanical analysis must be made for it. The finite element model of packer is set up and packer minimum setting load changes are calculated under different climb angle of cone. Results show that reduce the cone angle of climb can make the packer sealing load significantly lower.The calculation results provide the theoretical basis for the real operation.


Author(s):  
Jo¨rg Ro¨rup ◽  
Thomas E. Schellin ◽  
Helge Rathje

Many modern ships, particularly large containerships, are characterized by extreme bow flare, large stern overhang, and low torsional rigidity due to an open deck structural configuration. Software package GL ShipLoad was developed as an aid to assess the structural integrity of such ships. This software tool became the standard method to generate rule based loads for a global strength finite element analysis of sea going displacement ships. It efficiently generates loads based on first principles. A graphical user interface facilitates the convenient application of ship and cargo masses to the finite element model and aids in the selection of relevant design wave situations. User defined selection criteria, such as maximum values of rule based bending moments, shear forces, or torsional moments, specify which waves have to be chosen for the global strength analysis. This approach yields a reduced number of balanced load cases that are sufficient to dimension the hull structure. To adequately simulate roll motion, additional roll angles are analyzed that simulate realistic distributions of torsional moments over the ship length. A strength analysis of a typical post-panamax containership demonstrated the load generation procedure. First, efficiently modeled mass items were grouped into reusable assembled masses for the ship at hydrostatic equilibrium. Second, regular design wave scenarios were estimated, and hydrodynamic pressures for a large number of regular waves were computed. Third, a reduced number of relevant wave situations were automatically selected, and balanced hydrostatic, hydrodynamic, and inertia loads were applied to the finite element model. Enforced roll angles were found to contribute significantly to the initial torsional moment in the fore holds. Finally, based on a locally refined FE submodel of the hatch corners in way of the ship’s fore hold, a fatigue analysis was performed to assess effects of critical loading under enforced roll angles.


2011 ◽  
Vol 179-180 ◽  
pp. 186-191 ◽  
Author(s):  
Mao Tao Zhu ◽  
Zhong Wang ◽  
Wei Wei Zhang

Applying the method of finite element analysis, the finite element model of sub-frame of an automobile was built. With the aid of MSC software, longitudinal force operating mode which was pre-verified to be the most critical mode, was chosen for the static strength analysis and fatigue life simulation analysis of the sub-frame. Then the stress and fatigue life nephograms of the sub-frame were gotten. Comparison between finite element analysis and experiment result indicated that the finite element model can practically and properly reflect the real stress distribution of the sub-frame. Finally, based on this finite element model, some structure optimizations were done. After structure optimizations, the stress level was obviously improved. This method of FEA simulation together with experimental verification, significantly reduces the development cycle of new products, and is of important value in product design and quality improvement.


2014 ◽  
Vol 971-973 ◽  
pp. 380-389
Author(s):  
Jian Ning Wang ◽  
Gang Wu ◽  
Wei Yi Xie ◽  
Xin De Han ◽  
Ming Chao Gang

Abstract: The packer rubber stress in the bottom hole is more complex. Based on constitutive model of the packer rubber material, this paper determines such parameters as model constants, Poisson's ratio of rubber materials and elastic modulus by using experimental method, to build up the finite element model of center tube-rubber cylinder-casing for the purpose of stress analysis. Finally, the distribution regularity of rubber cylinder-casing contact stress and packer setting travel distance with varying loads is concluded. The results can provide the theoretical basis for further analysis of packer rubber sealing performance.


2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
B. Asgari ◽  
S. A. Osman ◽  
A. Adnan

The model tuning through sensitivity analysis is a prominent procedure to assess the structural behavior and dynamic characteristics of cable-stayed bridges. Most of the previous sensitivity-based model tuning methods are automatic iterative processes; however, the results of recent studies show that the most reasonable results are achievable by applying the manual methods to update the analytical model of cable-stayed bridges. This paper presents a model updating algorithm for highly redundant cable-stayed bridges that can be used as an iterative manual procedure. The updating parameters are selected through the sensitivity analysis which helps to better understand the structural behavior of the bridge. The finite element model of Tatara Bridge is considered for the numerical studies. The results of the simulations indicate the efficiency and applicability of the presented manual tuning method for updating the finite element model of cable-stayed bridges. The new aspects regarding effective material and structural parameters and model tuning procedure presented in this paper will be useful for analyzing and model updating of cable-stayed bridges.


2001 ◽  
Author(s):  
Y. W. Kwon ◽  
J. A. Lobuono

Abstract The objective of this study is to develop a finite element model of the human thorax with a protective body armor system so that the model can adequately determine the thorax’s biodynamical response from a projectile impact. The finite element model of the human thorax consists of the thoracic skeleton, heart, lungs, major arteries, major veins, trachea, and bronchi. The finite element model of the human thorax is validated by comparing the model’s results to experimental data obtained from cadavers wearing a protective body armor system undergoing a projectile impact.


Author(s):  
V. Ramamurti ◽  
D. A. Subramani ◽  
K. Sridhara

Abstract Stress analysis and determination of eigen pairs of a typical turbocharger compressor impeller have been carried out using the concept of cyclic symmetry. A simplified model treating the blade and the hub as isolated elements has also been attempted. The limitations of the simplified model have been brought out. The results of the finite element model using the cyclic symmetric approach have been discussed.


2013 ◽  
Vol 671-674 ◽  
pp. 1012-1015
Author(s):  
Zhao Ning Zhang ◽  
Ke Xing Li

Due to the environment, climate, loads and other factors, the pre-stress applied to the beam is not a constant. It is important for engineers to track the state of the pre-stress in order to ensure security of the bridge in service. To solve the problem mentioned above, the paper puts forward a new way to analyze the effective pre-stress using the displacement inversion method based on the inversion theory according to the measured vertical deflection of the bridge in service at different time. The method is a feasible way to predict the effective pre-stress of the bridge in service. Lastly, taking the pre-stressed concrete continuous rigid frame bridge for example, the effective pre-stress is analyzed by establishing the finite element model.


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