Development of the Auto-Fit Dial and its application to protective vests

2021 ◽  
pp. 004051752110608
Author(s):  
Jaewook Ryu ◽  
Sujin Park ◽  
Sumin Helen Koo ◽  
Giuk Lee

This study proposes the Auto-Fit Dial, which is suitable for high-speed fitting; it includes a function that can wind wire at high speed using an energy storage–release mechanism. The Auto-Fit Dial can store energy in advance in the spiral spring via the rotation of the knob cover, and it releases the stored energy to wind the wire when required by pushing the knob cover. Firstly, the concept design and working principle of the Auto-Fit Dial are explained. Next, a detailed design and structural stability analysis of the mechanical components are described based on the design formula and finite-element analysis. An Auto-Fit Dial prototype is manufactured according to the detailed design with the weight, diameter, and height of 9.7 g, 30.5 mm, and 16.7 mm, respectively. The maximum number of rotations is 5.2 turns, which can wind a wire up to a length of 320 mm. The pulling force applied when the Auto-Fit Dial pulls the wire is initially measured as 5.10 N. The time required to wind a 320 mm wire is 0.015 s, which results in an average speed of 21.33 m/s. Moreover, the Auto-Fit Sleeve is fabricated and applied to the arm sleeve to verify the utility of the Auto-Fit Dial, which combines wire and fabric. Finally, the Auto-Fit Vest is developed by applying a protective vest to the Auto-Fit Dial.

2014 ◽  
Vol 1021 ◽  
pp. 205-208
Author(s):  
Rui Xiong ◽  
Chun Dong Zhu ◽  
Xin Yu Li

The fine blanking press supports huge impact load and high-speed stamping frequency in the work process, and the deformation of the molds and the precision of components are significantly influenced by the deformation and vibration of the press. The frame under impact load and stamping frequency, thus the frame structure is the key factor to ensure the reliable work. To make the virtual prototype of the 12000KN fine blanking press frame meet requirements in the best way, the concept design of the frame was built. And optimal interval of the frame stiffness and first order natural frequency were find according to finite element analysis, which can lay the foundation for the design of an ideal frame.


2011 ◽  
Vol 335-336 ◽  
pp. 629-632
Author(s):  
Dan Jiang ◽  
Ping Yang ◽  
Ren Tian Ma

As a necessary component in pneumatic muscle, minimum switch and minimum mechanical hand, pen cylinder used as prime actuator possesses the characteristics of high speed actuation possible, easy installation, improved wear resistance and so on. The construction and working principle of the pen cylinder are introduced. Using 3-D stress field finite element analysis (FEA) method, the stress field distribution of pen cylinder with preload in mounting nut is analyzed. Simulation results are presented. The stress characteristics are compared between different preload in mounting nut and thickness of mounting bracket.


2020 ◽  
Vol 64 (1-4) ◽  
pp. 959-967
Author(s):  
Se-Yeong Kim ◽  
Tae-Woo Lee ◽  
Yon-Do Chun ◽  
Do-Kwan Hong

In this study, we propose a non-contact 80 kW, 60,000 rpm coaxial magnetic gear (CMG) model for high speed and high power applications. Two models with the same power but different radial and axial sizes were optimized using response surface methodology. Both models employed a Halbach array to increase torque. Also, an edge fillet was applied to the radial magnetized permanent magnet to reduce torque ripple, and an axial gap was applied to the permanent magnet with a radial gap to reduce eddy current loss. The models were analyzed using 2-D and 3-D finite element analysis. The torque, torque ripple and eddy current loss were compared in both models according to the materials used, including Sm2Co17, NdFeBs (N42SH, N48SH). Also, the structural stability of the pole piece structure was investigated by forced vibration analysis. Critical speed results from rotordynamics analysis are also presented.


Author(s):  
YK Wu ◽  
JL Mo ◽  
B Tang ◽  
JW Xu ◽  
B Huang ◽  
...  

In this research, the tribological and dynamical characteristics of a brake pad with multiple blocks are investigated using experimental and numerical methods. A dynamometer with a multiblock brake pad configuration on a brake disc is developed and a series of drag-type tests are conducted to study the brake squeal and wear behavior of a high-speed train brake system. Finite element analysis is performed to derive physical explanations for the observed experimental phenomena. The experimental and numerical results show that the rotational speed and braking force have important influences on the brake squeal; the trends of the multiblock and single-block systems are different. In the multiblock brake pad, the different blocks exhibit significantly different magnitudes of contact stresses and vibration accelerations. The blocks located in the inner and outer rings have higher vibration acceleration amplitudes and stronger vibration energies than the blocks located in the middle ring.


2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Qingzhong Mao ◽  
Yusheng Zhang ◽  
Yazhou Guo ◽  
Yonghao Zhao

AbstractThe rapid development of high-speed rail requires copper contact wire that simultaneously possesses excellent electrical conductivity, thermal stability and mechanical properties. Unfortunately, these are generally mutually exclusive properties. Here, we demonstrate directional optimization of microstructure and overcome the strength-conductivity tradeoff in copper wire. We use rotary swaging to prepare copper wire with a fiber texture and long ultrafine grains aligned along the wire axis. The wire exhibits a high electrical conductivity of 97% of the international annealed copper standard (IACS), a yield strength of over 450 MPa, high impact and wear resistances, and thermal stability of up to 573 K for 1 h. Subsequent annealing enhances the conductivity to 103 % of IACS while maintaining a yield strength above 380 MPa. The long grains provide a channel for free electrons, while the low-angle grain boundaries between ultrafine grains block dislocation slip and crack propagation, and lower the ability for boundary migration.


2012 ◽  
Vol 487 ◽  
pp. 203-207
Author(s):  
Gong Xue Zhang ◽  
Xiao Kai Shen

Purpose, with the application of workbench finite element analysis software, get the analysis results of DVG 850 high-speed vertical machining center via the modal analysis and harmonic response analysis. Use the calculation results for reference, put forward the improved method, and prove the credibility of the simulation analysis by testing DVG 850 prototype.


2021 ◽  
Vol 1 ◽  
pp. 3199-3208
Author(s):  
Emanuel Balzan ◽  
Pierre Vella ◽  
Philip Farrugia ◽  
Edward Abela ◽  
Glenn Cassar ◽  
...  

AbstractResearch funded projects are often concerned with the development of proof-of-concept products. Consequently, activities related to verification and validation testing (VVT) are often not considered in depth, even though various design iterations are carried out to refine an idea. Furthermore, the introduction of additive manufacturing (AM) has facilitated, in particular, the development of bespoke medical products. End bespoke products, which will be used by relevant stakeholders (e.g. patients and clinicians) are fabricated with the same manufacturing technologies used during prototyping. As a result, the detailed design stage of products fabricated by AM is much shorter. Therefore, to improve the market-readiness of bespoke medical devices, testing must be integrated within the development from an early stage, allowing better planning of resources. To address these issues, in this paper, a comprehensive VVT framework is proposed for research projects, which lack a VVT infrastructure. The framework builds up on previous studies and methods utilised in industry to enable project key experts to capture risks as early as the concept design stage.


Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4407
Author(s):  
Mbika Muteba

There is a necessity to design a three-phase squirrel cage induction motor (SCIM) for high-speed applications with a larger air gap length in order to limit the distortion of air gap flux density, the thermal expansion of stator and rotor teeth, centrifugal forces, and the magnetic pull. To that effect, a larger air gap length lowers the power factor, efficiency, and torque density of a three-phase SCIM. This should inform motor design engineers to take special care during the design process of a three-phase SCIM by selecting an air gap length that will provide optimal performance. This paper presents an approach that would assist with the selection of an optimal air gap length (OAL) and optimal capacitive auxiliary stator winding (OCASW) configuration for a high torque per ampere (TPA) three-phase SCIM. A genetic algorithm (GA) assisted by finite element analysis (FEA) is used in the design process to determine the OAL and OCASW required to obtain a high torque per ampere without compromising the merit of achieving an excellent power factor and high efficiency for a three-phase SCIM. The performance of the optimized three-phase SCIM is compared to unoptimized machines. The results obtained from FEA are validated through experimental measurements. Owing to the penalty functions related to the value of objective and constraint functions introduced in the genetic algorithm model, both the FEA and experimental results provide evidence that an enhanced torque per ampere three-phase SCIM can be realized for a large OAL and OCASW with high efficiency and an excellent power factor in different working conditions.


Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4143
Author(s):  
Youzheng Cui ◽  
Shenrou Gao ◽  
Fengjuan Wang ◽  
Qingming Hu ◽  
Cheng Xu ◽  
...  

Compared with other materials, high-volume fraction aluminum-based silicon carbide composites (hereinafter referred to as SiCp/Al) have many advantages, including high strength, small change in the expansion coefficient due to temperature, high wear resistance, high corrosion resistance, high fatigue resistance, low density, good dimensional stability, and thermal conductivity. SiCp/Al composites have been widely used in aerospace, ordnance, transportation service, precision instruments, and in many other fields. In this study, the ABAQUS/explicit large-scale finite element analysis platform was used to simulate the milling process of SiCp/Al composites. By changing the parameters of the tool angle, milling depth, and milling speed, the influence of these parameters on the cutting force, cutting temperature, cutting stress, and cutting chips was studied. Optimization of the parameters was based on the above change rules to obtain the best processing combination of parameters. Then, the causes of surface machining defects, such as deep pits, shallow pits, and bulges, were simulated and discussed. Finally, the best cutting parameters obtained through simulation analysis was the tool rake angle γ0 = 5°, tool clearance angle α0 = 5°, corner radius r = 0.4 mm, milling depth ap = 50 mm, and milling speed vc= 300 m/min. The optimal combination of milling parameters provides a theoretical basis for subsequent cutting.


2014 ◽  
Vol 488-489 ◽  
pp. 886-891
Author(s):  
Ai Jian Zheng ◽  
Feng Niu ◽  
Hai Jiang Zhu

This paper presents two nose cones models and their numerical calculation of aerodynamic noise in high speed airflow field combining the analysis theory of fluid dynamics with the acoustic boundary element analysis method. The noise sound pressure levels (SPL) of these two models are calculated under the different speed airflow. And we compare the SPL of the better model with that of commercial nose cone models. These simulated results show that the aerodynamic noise of the nose cone with a ellipsoid head has lower flow-induced noise than that of commercial nose cone models at relative high air flow velocities at most frequencies.


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