Reverse Design of the Roof Diamond Tool for Ruling Echelle Grating

2013 ◽  
Vol 552 ◽  
pp. 180-185 ◽  
Author(s):  
Guang Feng Shi ◽  
Guo Quan Shi ◽  
Lin Sen Song

For precise geometrical design and wear-resisting design of the roof diamond tool for ruling echelle grating of large area, computer aided reverse design was used to solve the problems. Firstly, based on the mechanical parameters of grating, Al film got from the nanoindentation test and nanoindenting simulated analysis. The optimized geometrical parameters of the roof diamond tool are got with an orthogonal analysis in a dynamical finite element model of simulating mechanical ruling. Then an equivalent resistance design method is put forward to improve the wearable ability of the roof diamond cutter with wear simulated analysis. Finally, a roof diamond tool of trial-lapping is presented for grating ruling investigation to verify the design effect.

Nanophotonics ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 3921-3930
Author(s):  
Valentina Di Meo ◽  
Alessio Crescitelli ◽  
Massimo Moccia ◽  
Annamaria Sandomenico ◽  
Angela M. Cusano ◽  
...  

AbstractThe steadily increasing demand for accurate analysis of vitamin D level, via measurement of its best general marker, 25-hydroxyvitamin D (25(OH)D), pushes for the development of novel automated assays capable of working at very low concentrations. Here, we propose a plasmonic biosensor of 25(OH)D3 (calcifediol) based on surface-enhanced infrared absorption spectroscopy, which exploits the resonant coupling between plasmonic nanoantennas and vibrational excitation of small molecules. Specifically, our proposed platform features a large-area (several mm2) metasurface made of gold nanoantennas fabricated on a silicon substrate, comprising different macroregions (“pixels”) of area 500 × 500 µm2. In each pixel, the nanoantenna geometrical parameters are tuned so as to support localized surface plasmon resonances (and hence large field enhancements at the nanoscale) within different regions of the infrared spectrum. As a result, a single chip is capable of performing analysis from the region of functional groups to that of fingerprint. Two different designs are fabricated via electron beam lithography, functionalized with a correlated antibody for the detection of 25(OH)D3, and characterized via Fourier-transform infrared spectroscopy. Our experiments demonstrate the capability to detect a concentration as low as 86 pmol/L, and an amount of immobilized small molecules of 25(OH)D3 monohydrate (molecular weight: 418.65 g/mol) as low as 4.31 amol over an area of 100 × 100 µm2.


2021 ◽  
Vol 11 (7) ◽  
pp. 3017
Author(s):  
Qiang Gao ◽  
Siyu Gao ◽  
Lihua Lu ◽  
Min Zhu ◽  
Feihu Zhang

The fluid–structure interaction (FSI) effect has a significant impact on the static and dynamic performance of aerostatic spindles, which should be fully considered when developing a new product. To enhance the overall performance of aerostatic spindles, a two-round optimization design method for aerostatic spindles considering the FSI effect is proposed in this article. An aerostatic spindle is optimized to elaborate the design procedure of the proposed method. In the first-round design, the geometrical parameters of the aerostatic bearing were optimized to improve its stiffness. Then, the key structural dimension of the aerostatic spindle is optimized in the second-round design to improve the natural frequency of the spindle. Finally, optimal design parameters are acquired and experimentally verified. This research guides the optimal design of aerostatic spindles considering the FSI effect.


2011 ◽  
Vol 346 ◽  
pp. 379-384
Author(s):  
Shu Bo Xu ◽  
Yang Xi ◽  
Cai Nian Jing ◽  
Ke Ke Sun

The use of finite element theory and modal analysis theory, the structure of the machine static and dynamic performance analysis and prediction using optimal design method for optimization, the new machine to improve job performance, improve processing accuracy, shorten the development cycle and enhance the competitiveness of products is very important. Selected for three-dimensional CAD modeling software-UG NX4.0 and finite element analysis software-ANSYS to set up the structure of the beam finite element model, and then post on the overall structure of the static and dynamic characteristic analysis, on the basis of optimized static and dynamic performance is more superior double wall structure of the beam. And by changing the wall thickness and the thickness of the inner wall, as well as the reinforcement plate thickness overall sensitivity analysis shows that changes in these three parameters on the dynamic characteristics of post impact. Application of topology optimization methods, determine the optimal structure of the beam ultimately.


2013 ◽  
Vol 690-693 ◽  
pp. 2554-2558
Author(s):  
Hua Jing Zhang ◽  
Zhi Tao Tang

The finite element method was adopted to predict the cutting temperature filed of workpiece surface when machining aerospace aluminum alloy 7050-T7451. Some key techniques such as the materials flow stress behavior, the separation of the chips with the workpiece, failure and fracture criterion, the tool-chip friction model were discussed in details. To validate the finite element model, the cutting temperature field of the chip was obtained by infrared thermal imaging system. The result revealed that the prediction model is credible. Based on the model, the effects of tool geometrical parameters such as flank wear, cutting edge inclination and corner radius on cutting temperature were analyzed.


2016 ◽  
Vol 850 ◽  
pp. 957-964
Author(s):  
Wei Zheng ◽  
Hong Zhang ◽  
Xiao Ben Liu ◽  
Le Cai Liang ◽  
Yin Shan Han

There is a potential for major damage to the pipelines crossing faults, therefore the strain-based design method is essential for the design of buried pipelines. Finite element models based on soil springs which are able to accurately predict pipelines’ responses to such faulting are recommended by some international guidelines. In this paper, a comparative analysis was carried out among four widely used models (beam element model; shell element model with fixed boundary; shell element model with beam coupled; shell element model with equivalent boundary) in two aspects: differences of results and the efficiency of calculation. The results show that the maximum and minimum strains of models coincided with each other under allowable strain and the calculation efficiency of beam element model was the highest. Besides, the shell element model with beam coupled or equivalent boundary provided the reasonable results and the calculation efficiency of them were higher than the one with fixed boundary. In addition, shell element model with beam coupled had a broader applicability.


2017 ◽  
Vol 6 (1) ◽  
pp. 63
Author(s):  
S. Makouei

In this paper, the strain insensitive single mode optical fiber with low nonlinear effects and ultra low bending loss (BL), appropriate for small curvature radius installation, is presented. The suggested design method is based on the reverse engineering which evaluates the refractive index profile considering proper mode field diameter (MFD) value. Then, so as to attain the desired bending loss and strain response for the optical fiber, the optimization tool of the evolutionary genetic algorithm (GA) is employed to determine the optical and geometrical parameters of the structure. In the first designed fiber, the calculations for BL, MFD, effective area (Aeff), and effective refractive index (neff) sensitivity to strain in the well-known wavelength of 1.55 µm are 0.0018 dB per each turn of 5 mm curvature radius, 8.53 µm, 58 µm2, and 4.5 × 10-8 µɛ-1, respectively. Furthermore, the effect of placing raised outer cladding in the fiber structure is investigated which exhibits the MFD of 8.63 µm, 0.0093 dB BL for single turn of 5 mm radius, and 87 µm2 Aeff at 1.55 µm. In this case the strain sensitivity of 6.7 × 10-8 µɛ-1 is calculated for the neff. The mentioned effective area is magnificently large in the domain of bend insensitive fibers. In the meantime, the designed structures are insensitive to strain which is a crucial feature in applications with small curvature radius.


Micromachines ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1038
Author(s):  
Vinh-Tan Nguyen ◽  
Jason Yu Chuan Leong ◽  
Satoshi Watanabe ◽  
Toshimitsu Morooka ◽  
Takayuki Shimizu

The ink drop generation process in piezoelectric droplet-on-demand devices is a complex multiphysics process. A fully resolved simulation of such a system involves a coupled fluid–structure interaction approach employing both computational fluid dynamics (CFD) and computational structural mechanics (CSM) models; thus, it is computationally expensive for engineering design and analysis. In this work, a simplified lumped element model (LEM) is proposed for the simulation of piezoelectric inkjet printheads using the analogy of equivalent electrical circuits. The model’s parameters are computed from three-dimensional fluid and structural simulations, taking into account the detailed geometrical features of the inkjet printhead. Inherently, this multifidelity LEM approach is much faster in simulations of the whole inkjet printhead, while it ably captures fundamental electro-mechanical coupling effects. The approach is validated with experimental data for an existing commercial inkjet printhead with good agreement in droplet speed prediction and frequency responses. The sensitivity analysis of droplet generation conducted for the variation of ink channel geometrical parameters shows the importance of different design variables on the performance of inkjet printheads. It further illustrates the effectiveness of the proposed approach in practical engineering usage.


Author(s):  
Diego Maria Barbieri ◽  
Yuechi Chen ◽  
Enrico Mazzarolo ◽  
Bruno Briseghella ◽  
Angelo Marcello Tarantino

Hollow core slab bridges are constructed by placing prefabricated or prestressed box beams adjacent to each other, grouting the small longitudinal space (hinge-joint) between the slabs and casting a reinforced concrete deck. The longitudinal cracking appearing at hinge-joint locations leads to a premature deterioration of the deck. This paper presents a theoretical and experimental study of a hollow core slab bridge composed of three beams and a cast-in-place deck. A real-size specimen was built according to Chinese code specifications. The behavior of the longitudinal joints was investigated by applying the standard vehicle load. The tests do not highlight any longitudinal cracks. A finite element model was created from the experimental data. A finite element parametric analysis revealed some practical design indications regarding the following inputs: deck thickness, concrete strength, and hinge-joint steel bars. Furthermore, these analyses testify that C-shape and X-shape stirrups do not play an active role in preventing the joint longitudinal cracks. This research confirms the reliability of the design method, at least for static loads, while further studies are needed to investigate the effect of both periodical loadings and different temperatures on upper and lower surfaces of the beams.


2010 ◽  
Vol 654-656 ◽  
pp. 1614-1617 ◽  
Author(s):  
Sheng Zhi Li ◽  
Hai Yan Bao ◽  
Zhi Chao Zhang ◽  
Yang Hua Li ◽  
Gong Ming Long

the aid of commercially available software MSC.SuperForm, a 3-D finite element model has been established to simulate the rolling process of steel tubes on the stretch reducing mill (SRM) with group centralized differential drive in certain factories. A special effort was made to analyze the fluctuation of transverse wall thickness uniformity. It was found that the wall thickness of each stand was accumulated in the original pass 50°~60° along the circumferential direction, which caused the formation of the inner hexagon defects and worsen. In view of this, this paper proposes a modified roll pass design method which uses the interactive technology of CAD graph curve and MATLAB equation. By means of decreasing the lateral curvature of roll pass contour curve to enlarge the contact length between the tube and groove, also the rolling process using the new pass system were simulated and analyzed. The results indicate that the design of such polygonal roll pass can be effective in improving the inner hexagon defects.


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