A simulation of void variation in wood-strand composites during consolidation

Holzforschung ◽  
2009 ◽  
Vol 63 (3) ◽  
Author(s):  
Peng Li ◽  
Chunping Dai ◽  
Sunguo Wang

Abstract The void variation in a wood-strand composite mat during consolidation was simulated using computer-aided design, finite element analysis, and computer image processing. Compared with prior models, this simulation provided a different and more visual approach to analyzing the mat structure, particularly the void variation during consolidation. The simulated results showed similar trends to the experimental data. The size of voids in the final panel decreased with the panel density and increased with the strand thickness, whereas the relationship between the void size and the strand length was non-linear. The wood-strand density and strand thickness had a much greater effect on the non-linear void variation than the wood strand width and length. The simulated results are beneficial to improve the fundamental understanding of composite processing and performance characteristics.

2015 ◽  
Vol 645-646 ◽  
pp. 70-74 ◽  
Author(s):  
Min Zhong ◽  
Yu Hang Zhao ◽  
Shou Mian Chen ◽  
Ming Li ◽  
Shao Hai Zeng ◽  
...  

An embedded SiGe layer was applied in the source/drain areas (S/D) of a field-effect transistor to boost the performance in the p channels. Raised SiGe S/D plays a critical role in strain engineering. In this study, the relationship between the SiGe overfilling and the enhancement of channel stress was investigated. Systematic technology computer aided design (TCAD) simulations of the SiGe overfill height in a 40 nm PMOS were performed. The simulation results indicate that a moderate SiGe overfilling induces the highest stress in the channel. Corresponding epitaxial growth experiments were done and the obtained experimental data was in good agreement with the simulation results. The effect of the SiGe overfilling is briefly discussed. The results and conclusions presented within this paper might serve as useful references for the optimization of the embedded SiGe stressor for 40 nm logic technology node and beyond.


2021 ◽  
Vol 143 (11) ◽  
Author(s):  
Muhammad Hassan ◽  
Hussain Ahmed Tariq ◽  
Muhammad Anwar ◽  
Talha Irfan Khan ◽  
Asif Israr

Abstract This paper showcases the designing, fabrication, and performance evaluation of 90-deg alpha-type Stirling engine. The diameters of the hot and cold cylinder are 50 mm and 44 mm, respectively, with a stroke length of 70 mm. The computer-aided design (CAD) model is developed by keeping in mind the ease of manufacturing, maintenance, bearing replacements, and lubrication. After fabrication, the engine is tested by heating the hot cylinder with air as a working fluid. The engine delivered peak power of 155 watts at the temperature of 1123 K and 968 K for hot and cold cylinders, respectively. This developed prototype can be commissioned with the solar parabolic concentrator in the future based on the smooth operation while delivering power.


2019 ◽  
Vol 31 ◽  
pp. 103-111 ◽  
Author(s):  
Yu-shan Chang ◽  
Mavis Yi-Ching Chen ◽  
Meng-Jung Chuang ◽  
Chia-hui Chou

2021 ◽  
Author(s):  
Paulina Zenowicz

There is a need to design new, lighter aircraft structures, which has a direct impact on the safety and costs of aircraft maintenance. One of basic parts of an aircraft is ites landing gear, whose main functions are to enable taxiing, safe landing, take-off, and to assist the remainder of ground operations. Landing gear failures are usually related to metallurgy, processing, environment, design, and causes of overload. These are conditions that can be prevented using modern methods to calculate the strength of such a landing gear in various conditions. The paper presents stages of a simulation study of the fixed three-wheeled spring landing gear for an ultralight aircraft. Analysis of forces acting on the landing gear during drop test and their implementation by numerical computer methods allowed for the creation of a model in the CAD (Computer-Aided Design) tool and its FEA (Finite Element Analysis). These results were compared between a modeled classic spring landing gear and the one made of composite materials. The further goal of the research will be to build a drop test stand for a small landing gear used in airplanes and drones. This method has a significant impact on simplifying the design of the landing gear, its modeling, and optimization.


Author(s):  
Devarajan Ramanujan ◽  
William Z. Bernstein

VESPER (Visual Exploration of Similarity and PERformance) is a visual analytics system for exploring similarity metrics and performance metrics derived from computer-aided design (CAD) repositories. It consists of (1) a data processing module that allows analysts to input custom similarity metrics and performance metrics, (2) a visualization module that facilitates navigation of the design spaces through coordinated, interactive visualizations, and (3) a report generation module that allows analysts to export lifecycle data of selected repository items as well as the input metrics for further external validation. In this paper, we discuss the need, design rationale, and implementation details for VESPER. We then apply VESPER to (1) sustainability-focused exploration of parts, and (2) exploration of tool wear and surface roughness in machined parts.


2021 ◽  
Vol 111 (2) ◽  
pp. 66-77
Author(s):  
M. Othmani ◽  
K. Zarbane ◽  
A. Chouaf

Purpose: The present work aims to investigate the effect of many infill patterns (rectilinear, line, grid, triangles, cubic, concentric, honeycomb, 3D honeycomb) and the infill density on the mechanical tensile strength of an Acrylonitrile Butadiene Styrene (ABS) test specimen manufactured numerically by FDM. Design/methodology/approach: Computer-Aided Design (CAD) software has been used to model the geometry and the mesostructure of the test specimens in a fully automatic manner from a G-code file by using a script. Then, a Numerical Design of Experiments (NDoE) has been carried out by using Taguchi method and the Analysis of Variance (ANOVA). The tensile behaviour of these numerical test specimens has been studied by the Finite Element Analysis (FEA). Findings: The FEA results showed that a maximal Ultimate Tensile Strength (UTS) was reached by using the ‘concentric’ infill pattern combined with an infill density of 30%. The results also show that the infill pattern and the infill density are significant factors. Research limitations/implications: The low infill densities of 20% and 30% that have already been used in many previous studies, we have also applied it in order to reduce the time of the simulations. Indeed, with high infill density, the simulations take a very excessive time. In an ongoing study, we predicted higher percentages. Practical implications: This study provided an important modelling tool for the design and manufacture of functional parts and helps the FDM practitioners and engineers to manufacture strong and lightweight FDM parts by choosing the optimal process parameters. Originality/value: This study elucidated the effect of various infill patterns on the tensile properties of the test specimens and applied for the first time a NDoE using numerical test specimens created by the mesostructured approach, which considerably minimized the cost of the experiments while obtaining an error of 6.8% between the numerical and the experimental values of the UTS.


Author(s):  
Hossam S. Badawi ◽  
Sherif A. Mourad ◽  
Sayed M. Metwalli

Abstract For a Computer Aided Design of a concrete truck mixer, a six cubic meter concrete mixer drum is analyzed using the finite element method. The complex mixer drum structure is subjected to pressure loading resulting from the plain concrete inside the drum, in addition to its own weight. The effect of deceleration of the vehicle and the rotational motion of the drum on the reactions and stresses are also considered. Equivalent static loads are used to represent the dynamic loading effects. Three-dimensional shell elements are used to model the drum, and frame elements are used to represent a ring stiffener around the shell. Membrane forces and bending stresses are obtained for different loading conditions. Results are also compared with approximate analysis. The CAD procedure directly used the available drafting and the results were used effectively in the design of the concrete mixer drum.


Author(s):  
Tahir Abbas Jauhar ◽  
Soonhung Han ◽  
Soonjo Kwon

Abstract Computer-aided design, engineering, and manufacturing (CAx) have improved product design and development. The associativity of revised design in native files for downstream applications, assembly design, finite element analysis, and numerical control (NC) manufacturing has been supported by homogeneous CAx systems. However, heterogeneous CAx environments have issues when neutral models are revised and re-imported because the required identification information is missing. This results in a problem of the associativity of neutral models. In this study, different computer-aided design (CAD) applications have been analyzed with respect to their capabilities for import and export of neutral models with identification information. A tool has been selected to demonstrate the key findings. Moreover, future directions have been discussed to solve associativity issues in design re-import based on neutral models.


Sign in / Sign up

Export Citation Format

Share Document