Mechanical Ruling of Diffraction Grating: Part II — Experimental Investigation and Numerical Simulation

2016 ◽  
Author(s):  
Qinghua Wang ◽  
Ninggang Shen ◽  
Baoqing Zhang ◽  
Hongtao Ding
Keyword(s):  
Diffraction Grating ◽  
Three Dimensional ◽  
Fe Analysis ◽  
Temperature Fields ◽  
Fe Model ◽  
Preparation Process ◽  
Gradient Plasticity ◽  
Film Preparation ◽  
Scratch Tests ◽  
Series Study

This is Part II of a two-part series study on mechanical ruling of diffraction grating. In Part I, effects of the Al film preparation process on the film attributes were investigated in terms of surface morphology, microstructure and mechanical properties using SEM, XRD, nanoindentation and scratch tests. In this part, mechanical ruling experiments were carried out on the prepared Al films with various thicknesses. The effect of ruling loads on the groove geometry were investigated. The tool wear after the mechanical ruling tests was inspected. A three-dimensional thermomechanical coupled finite element (FE) model was developed to predict the deformation and temperature fields during mechanical ruling. The strain gradient plasticity model was used in the FE analysis to model the size effect during the process. The multi-pass effect on the variation of groove geometry was predicted and analyzed with the FE model under different loading conditions.

Experimental Investigation and Numerical Analysis of Mechanical Ruling for an Aluminum-Coated Diffraction Grating

2016 ◽  
Vol 139 (2) ◽  
Author(s):  
Baoqing Zhang ◽  
Qinghua Wang ◽  
Ninggang Shen ◽  
Hongtao Ding
Keyword(s):  
Diamond Tool ◽  
Three Dimensional ◽  
Temperature Fields ◽  
Fe Model ◽  
Loading Conditions ◽  
Gradient Plasticity ◽  
X Ray Diffraction ◽  
Film Properties ◽  
Scratch Tests ◽  
Deposited Film

The mechanical ruling process using a diamond tool is an important method for fabrication of low-density diffraction gratings. In mechanical ruling, a deposited film of aluminum or gold is mechanically burnished by the diamond tool to form equally spaced and high-quality grooves. The goal of this work is to evaluate the effects of Al film properties and ruling tool loading conditions on the resultant groove formation. The microstructure of the Al film is first studied using scanning electron microscope (SEM) and X-ray diffraction (XRD). The mechanical properties of the Al film are measured by nano-indentation and scratch tests. Mechanical ruling experiments are then carried out on a 10.5 μm thick Al film under various ruling loads ranging from 20 to 105 g. The groove geometry is investigated, and the tool wear of the diamond tool is inspected after the mechanical ruling tests. Finally, a three-dimensional (3D) thermomechanical-coupled finite-element (FE) model is developed to predict the deformation and temperature fields for the micron-scale groove formation by incorporating the Al film properties and a strain-gradient plasticity for modeling the size effect. Multiruling pass simulations are performed to analyze the groove formation under different loading conditions. Through comparison of simulation results with experimental measurement, this model is demonstrated as a useful numerical tool for modeling the mechanical ruling process using a diamond tool.

Mechanical Ruling of Diffraction Grating: Part I — Aluminum Film Preparation and Characterization

2016 ◽  
Author(s):  
Qinghua Wang ◽  
Baoqing Zhang ◽  
Ninggang Shen ◽  
Hongtao Ding
Keyword(s):  
Mechanical Properties ◽  
Diffraction Grating ◽  
Aluminum Film ◽  
Preparation Technique ◽  
Simulation Studies ◽  
High Quality ◽  
Complete Study ◽  
Film Preparation ◽  
Scratch Tests ◽  
Series Study

This is Part I of a two part series study on mechanical ruling of diffraction grating. Mechanical ruling is a major method for fabricating diffraction grating. In mechanical ruling, the first step is to prepare the Al film. High quality preparation technique is needed to satisfy the requirements of the thickness and the mechanical properties of the film. The purpose of this paper is to present a complete study on the preparation technique and mechanical properties of the Al film used for mechanical ruling of diffraction grating. XRD and SEM experiments and analysis were conducted to investigate the microstructure of the Al film and the mechanical properties of the Al film were measured using nanoindentation and scratch tests. The Al film exhibits favorable mechanical properties which will the key for the experimental and numerical simulation studies of mechanical ruling of diffraction grating.

scholarly journals Numerical Investigation on Steel Square HSS Columns Strengthened with Polymer-mortar

2019 ◽  
pp. 1-25
Author(s):  
Khaled M. El-Sayed ◽  
Ahmed S. Debaiky ◽  
Nader N. Khalil ◽  
Ibrahim M. El-Shenawy
Keyword(s):  
Three Dimensional ◽  
Shell Element ◽  
Fe Analysis ◽  
Experimental Results ◽  
Fe Model ◽  
Cross Sectional ◽  
Axial Strength ◽  
Polymer Mortar ◽  
Slender Columns ◽  
Good Agreement

This paper presents the results of finite element (FE) analysis of axially loaded square hollow structural steel (HSS) columns, strengthened with polymer-mortar materials. Three-dimensional nonlinear FE model of HSS slender columns were developed using thin-shell element, considering geometric and material nonlinearity. The polymer-mortar strengthening layer was incorporated using additional layers of the shell element. The FE model has been performed and then verified against experimental results obtained by the authors [1]. Good agreement was observed between FE analysis and experimental results. The model was then used in an extended parametric study to examine selected AISC square HSS columns with different cross-sectional geometries, slenderness ratios, thicknesses of mortar strengthening layer, overall geometric imperfections, and level of residual stresses. The effectiveness of polymer-mortar in increasing the column’s axial strength is observed. The study also demonstrated that polymer-mortar strengthening materials is more effective for higher slenderness ratios. An equivalent steel thickness is also accounted for the mortar strengthened HSS columns to discuss the effectiveness of polymer-mortar strengthening system. The polymer-mortar strengthening system is more effective for HSS columns with higher levels of out-of-straightness. Level of residual stress has a slight effect on the gain in the column’s axial strength strengthened with polymer-mortar.

The biomechanical study of cervical spine: A Finite Element Analysis

2021 ◽  
pp. 039139882199549
Author(s):  
Pechimuthu Susai Manickam ◽  
Sandipan Roy
Keyword(s):  
Finite Element ◽  
Cervical Spine ◽  
Degrees Of Freedom ◽  
Three Dimensional ◽  
Biomechanical Study ◽  
Fe Analysis ◽  
Von Mises Stress ◽  
Fe Model ◽  
Element Analysis ◽  
End Plate

The biomechanical study helps us to understand the mechanics of the human cervical spine. A three dimensional Finite Element (FE) model for C3 to C6 level was developed using computed tomography (CT) scan data to study the mechanical behaviour of the cervical spine. A moment of 1 Nm was applied at the top of C3 vertebral end plate and all degrees of freedom of bottom end plate of C6 were constrained. The physiological motion of the cervical spine was validated using published experimental and FE analysis results. The von Mises stress distribution across the intervertebral disc was calculated along with range of motion. It was observed that the predicted results of functional spine units using FE analysis replicate the real behaviour of the cervical spine.

scholarly journals Behavior of bolted lap joints in above ground liquid-filled steel cylindrical tanks

2021 ◽  
Author(s):  
Mehdi Moslemi ◽  
M. Reza Kianoush
Keyword(s):  
Three Dimensional ◽  
Lap Joints ◽  
Fe Analysis ◽  
Main Concern ◽  
Fe Model ◽  
Wide Range ◽  
Cylindrical Tanks ◽  
Bolt Arrangement ◽  
Two Stages ◽  
Good Agreement

Leakage is the main concern in steel bolted liquid tanks. In this study, the performance of this type of construction is investigated using a detailed finite element (FE) analysis. The validity of AWWA design practice in terms of the safe design of this type of structure at a wide range of service loads is evaluated. The FE analysis is performed in two stages using shell and solid elements in a three-dimensional ANSYS environment including the effect of geometric nonlinearity. The proposed FE model is capable to estimate the ultimate behaviors such as capacity curve, yield/failure pattern, and the occurrence of ovalling and curling. The FE results are compared with experimental ones and a good agreement is found. This study shows that the bolt arrangement selected in design can efficiently improve joint performance. It is recommended to use the limited deformation criterion in the leak-resistant design of bolted lap joints.

Effects of Parameters on Fine Blanking of Steel Synchronizer Ring Teeth

2014 ◽  
Vol 941-944 ◽  
pp. 1671-1677
Author(s):  
Mei Zhang ◽  
Lin Hua ◽  
Yan Li Song ◽  
Hua Jie Mao ◽  
Yan Xiong Liu
Keyword(s):  
Finite Element ◽  
Hydrostatic Stress ◽  
Three Dimensional ◽  
Fe Analysis ◽  
Fe Model ◽  
Analysis Software ◽  
Fine Blanking ◽  
Die Roll ◽  
Cut Surface ◽  
Deform 3D

The influences of parameters on fine blanking of steel synchronizer ring teeth have been studied in this paper. Based on the finite element (FE) analysis software DEFORM-3D, a three-dimensional FE model of fine blanking of steel synchronizer ring teeth was established. By analyzing the distribution of hydrostatic stress, the length of smooth cut surface and the height of die-roll, the influence of parameters (i.e., counterforce, blanking clearance and V-ring indenter form) on the cut surface of synchronizer ring teeth were discussed. The quantitative relationships between parameters and the cut surfaces were established. The results show that: Increasing counterforce, decreasing blanking clearance and V-ring indenter located on die are conducive to increase the length of smooth cut surface and to decrease the height of die-roll. These results have a certain guiding significance on the production process of fine blanking of steel synchronizer ring.

scholarly journals Numerical Analysis of Temperature Field in a Disc Brake at Different Cover Angle of the Pad

2014 ◽  
Vol 8 (4) ◽  
pp. 185-188
Author(s):  
Piotr Grześ
Keyword(s):  
Finite Element ◽  
Temperature Field ◽  
Three Dimensional ◽  
Temperature Fields ◽  
Disc Brake ◽  
Fe Model ◽  
Dimensional Finite Element ◽  
Braking Process ◽  
The Moment ◽  
Three Dimensional Finite Element

Abstract In the paper an influence of the cover angle of the pad on temperature fields of the components of the disc brake is studied. A three-dimensional finite element (FE) model of the pad-disc system was developed at the condition of equal temperatures on the contacting surfaces. Calculations were carried out for a single braking process at constant deceleration assuming that the contact pressure corresponds with the cover angle of the pad so that the moment of friction is equal in each case analysed. Evolutions and distributions of temperature both for the contact surface of the pad and the disc were computed and shown.

Pavement Damage Due to Conventional and New Generation of Wide-Base Super Single Tires

2005 ◽  
Vol 33 (4) ◽  
pp. 210-226 ◽  
Author(s):  
I. L. Al-Qadi ◽  
M. A. Elseifi ◽  
P. J. Yoo ◽  
I. Janajreh
Keyword(s):  
Carrying Capacity ◽  
Material Properties ◽  
Three Dimensional ◽  
Fe Analysis ◽  
Load Carrying Capacity ◽  
Inflation Pressure ◽  
3D Finite Element ◽  
Load Carrying ◽  
Pavement Damage ◽  
New Generation

Abstract The objective of this study was to quantify pavement damage due to a conventional (385/65R22.5) and a new generation of wide-base (445/50R22.5) tires using three-dimensional (3D) finite element (FE) analysis. The investigated new generation of wide-base tires has wider treads and greater load-carrying capacity than the conventional wide-base tire. In addition, the contact patch is less sensitive to loading and is especially designed to operate at 690kPa inflation pressure at 121km/hr speed for full load of 151kN tandem axle. The developed FE models simulated the tread sizes and applicable contact pressure for each tread and utilized laboratory-measured pavement material properties. In addition, the models were calibrated and properly validated using field-measured stresses and strains. Comparison was established between the two wide-base tire types and the dual-tire assembly. Results indicated that the 445/50R22.5 wide-base tire would cause more fatigue damage, approximately the same rutting damage and less surface-initiated top-down cracking than the conventional dual-tire assembly. On the other hand, the conventional 385/65R22.5 wide-base tire, which was introduced more than two decades ago, caused the most damage.

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