scholarly journals Effect of Glass Bubbles on Friction and Wear Characteristics of PDMS-Based Composites

Coatings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 603
Author(s):  
Sung-Jun Lee ◽  
Gang-Min Kim ◽  
Chang-Lae Kim

The purpose of this study is to improve the mechanical durability and surface frictional characteristics of polymer/ceramic-based composite materials. Polydimethylsiloxane (PDMS)/glass bubble (GB) composite specimens are prepared at various weight ratios (PDMS:GB) by varying the amount of micro-sized GBs added to the PDMS. The surface, mechanical, and tribological characteristics of the PDMS/GB composites are evaluated according to the added ratios of GBs. The changes in internal stress according to the indentation depth after contacting with a steel ball tip to the bare PDMS and PDMS/GB composites having different GB densities are compared through finite element analysis simulation. The elastic modulus is proportional to the GB content, while the friction coefficient generally decreases as the GB content increases. A smaller amount of GB in the PDMS/GB composite results in more surface damage than the bare PDMS, but a significant reduction in wear rate is achieved when the ratio of PDMS:GB is greater than 100:5.

Actuators ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 81
Author(s):  
Atif Zahid ◽  
Faisal Khan ◽  
Naseer Ahmad ◽  
Irfan Sami ◽  
Wasiq Ullah ◽  
...  

A dual mover yokeless multi-tooth (DMYMT) permanent magnet flux switching motor (PM-FSM) design is presented in this article for ropeless elevator applications. The excitation sources, including a field winding and permanent magnet, are on the short mover in the proposed design structure, whereas the stator is a simple slotted iron core, thus reducing the vertical transportation system cost. The operational principle of the proposed DMYMT in PM-FSM is introduced. The proposed dual mover yokeless multi-tooth Permanent Magnet Flux Switching Motor is analyzed and compared for various performance parameters in a Finite Element Analysis package. The proposed machine has high thrust force and cost-effectiveness compared to conventional dual permanent magnet motor. Finally, this paper also develops an analytical model for the proposed structure, validated by comparing it with Finite Element Analysis simulation results. Results show good agreement between analytical prediction and Finite Element Analysis results.


2021 ◽  
pp. 1-9
Author(s):  
Jie Zhang ◽  
Ping Ye ◽  
Lizheng Zhang ◽  
Hongliu Wu ◽  
Tianxi Chi ◽  
...  

BACKGROUND: The treatment of adolescent patients with distal femoral cancer has always been a concern. The limb-salvage, regarded as a mainstream treatment, had been developed in recent years, but its application in children still remains challenging. This is because it can lead to potential limb-length discrepancy from the continued normal growth of the contralateral lower body. The extendable prosthesis could solve this problem. The principle is that it can artificially control the length of the prosthesis, making it consistent with the length of the side of the lower limbs. However, this prosthesis has some complications. The extendable prosthesis is classified into invasive and minimally invasive, which extends the prosthesis with each operation. OBJECTIVE: We designed a new non-invasive prosthesis that can be extended in the body. Based on the non-invasive and extendable characteristics, we need to verify the supporting performance of this prosthesis. METHODS: We carried out a mechanical testing method and finite element analysis simulation. CONCLUSION: The support performance and non-invasively extension of this prosthesis were verified.


2020 ◽  
Vol 1507 ◽  
pp. 082014
Author(s):  
L B Zou ◽  
C G Yu ◽  
G B Feng ◽  
J L Zhong ◽  
X F Liu ◽  
...  

Author(s):  
David Ross-Pinnock ◽  
Glen Mullineux

Control of temperature in large-scale manufacturing environments is not always practical or economical, introducing thermal effects including variation in ambient refractive index and thermal expansion. Thermal expansion is one of the largest contributors to measurement uncertainty; however, temperature distributions are not widely measured. Uncertainties can also be introduced in scaling to standard temperature. For more complex temperature distributions with non-linear temperature gradients, uniform scaling is unrealistic. Deformations have been measured photogrammetrically in two thermally challenging scenarios with localised heating. Extended temperature measurement has been tested with finite element analysis to assess a compensation methodology for coordinate measurement. This has been compared to commonly used uniform scaling and has outperformed this with a highly simplified finite element analysis simulation in scaling a number of coordinates at once. This work highlighted the need for focus on reproducible temperature measurement for dimensional measurement in non-standard environments.


2014 ◽  
Vol 926-930 ◽  
pp. 52-55
Author(s):  
Lian Feng Lai ◽  
Cheng Hui Gao ◽  
Jian Meng Huang

A three-dimensional W-M fractal sliding model of double rough surfaces was established, and the factors of interface shear strength influenced the whole sliding process was considered. The velocity in Z direction of sliding processes was analyzed using the finite element analysis and taking into account of adhesion factors in the process of contact. The numerical results showed that the velocity in Z direction's fluctuation is larger, and the higher-frequency component is more with the decrease of the interface shear strength. Compared with experimental results and related documents, it is concluded the rationality of the results. The contact model between two rough solids will lay a foundation to further research on the substance of the process of friction and wear.


2014 ◽  
Vol 543-547 ◽  
pp. 3-6
Author(s):  
Jie Min ◽  
Hai Sheng Wang ◽  
De Wei Guo ◽  
Wen Bin Zhang

DEFORM is a software used for FEA (Finite Element Analysis) simulation. By using this software, I take a research on the procedure when a steel billet with defect of artificial loosening is drawn out in a simulated environment. Then I build a FEA model about the loosening and compaction of a large-sized rotor and stimulate the procedure in accordance with current craft card involving rotor forging. Finally, I get a result: the relative density of the loose area reaches up to 85% after the first drawing-out process (note: forging ratio 1.47). After simulating the procedure of chamfering on a billet which has been already drawn out, I found that chamfering had little substantial impact on the its loosening and compaction.


2013 ◽  
Vol 573 ◽  
pp. 69-75 ◽  
Author(s):  
Xiao Hui Chen ◽  
Duo Min Li ◽  
Jian Bei Zhu ◽  
Xu Chen

A series of ratcheting experiments and finite element analysis simulation under bending loading for Z2CND18.12N stainless steel elbows were carried out. Chaboche and modified Ohno-Wang model are applied to evaluate structural ratcheting response simulations. It is found that ratcheting strain initiates firstly in the hoop direction and increases in the axial direction with the increasing of loading. The Ratcheting strain rate grows with the increase of the reversed in-plane bending load or internal pressure for both specimens with different loadings. Comparison of simulation and experiment showed that modified Ohno-Wang model presented simulation more reasonably.


2021 ◽  
Vol 6 (3) ◽  
Author(s):  
Nicholas S Gukop ◽  
Peter M Kamtu ◽  
Bildad D Lengs ◽  
Alkali Babawuya ◽  
Adesanmi Adegoke

Investigation on the effect of mesh density on the analysis of simple support bracket was conducted using Finite element analysis simulation. Multiple analyses were carried out with mesh refinement from coarse mesh of 3.5 mm to a high-quality fine mesh with element size of 0.35 mm under 15 kN loading. Controlled mesh analysis was also conducted for the same loading. At the mesh size of 0.35 mm, it has a maximum stress value of 42.7 MPa. As the element size was reduced, it was observed that below 1.5 mm (higher mesh density) there was no significant increase in the peak stress value; the stress at this level increased by 0.028 % only. Further decreased of mesh size shows insignificant effect on the stresses and displacements for the high-quality fine mesh analysis. The application of High-quality mesh control analysis showed a significant reduction in the computation time by more than 90%. Regardless of the reduction in computation time, the controlled mesh analysis achieved more than 99% accuracy as compared to high-quality fine mesh analysis. Keywords— Computation time, Finite Element Analysis, Mesh density, Support Bracket.


2016 ◽  
Vol 22 (5) ◽  
pp. 848-856 ◽  
Author(s):  
Behrokh Khoshnevis ◽  
Xiao Yuan ◽  
Behnam Zahiri ◽  
Jing Zhang ◽  
Bin Xia

Purpose This paper aims to report on the experiments with the Contour Crafting Automated Construction process using sulfur concrete as the choice of construction material. Design/methodology/approach Several experiments have been performed at centimeter and meter scales. A finite element analysis simulation model for the behavior of sulfur concrete-based structures has been developed. Experimental results were compared with the results of simulation. Findings Sulfur concrete has numerous terrestrial applications and is potentially an ideal construction material for planetary construction. Originality/value Experimental samples of sulfur concrete were fabricated using a novel mixer/extrusion system. The mechanism was proven to be durable and stable after more than 500 h of work.


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