Effect of autoclave process on the quality of thermoplastic composite truncated cones manufactured using automated fiber placement technique

2015 ◽  
Vol 22 (2) ◽  
pp. 175-186
Author(s):  
Farjad Shadmehri ◽  
Xiao Cai ◽  
Mehdi Hojjati ◽  
Jihua Chen ◽  
Suong V. Hoa
Keyword(s):  
Finite Element ◽  
Modal Analysis ◽  
Natural Frequencies ◽  
Thermoplastic Composite ◽  
Fiber Placement ◽  
Autoclave Process ◽  
Stiffness Properties ◽  
Automated Fiber Placement ◽  
Placement Technique

AbstractIn order to investigate the effect of autoclave process on the stiffness properties of thermoplastic composite truncated cones made by automated fiber placement technique (AFP), two short truncated cones were made out of advanced thermoplastic composite material (carbon fiber/PEEK). Then, the truncated cones were tested by impulse excitation of vibration to get experimental natural frequencies. Tensile and compression test coupons were made out of the same material using hand layup and autoclave process, and stiffness properties were characterized experimentally. Furthermore, finite element analysis was performed to extract theoretical natural frequencies using material properties obtained from coupon testing. Comparison between the natural frequencies obtained using the finite element method and experimental modal analysis was conducted. Furthermore, the two truncated cones were treated inside the autoclave, and changes in the thickness and density were measured. After autoclave treatment, experimental modal analysis was repeated to investigate the possible changes in natural frequencies. The finite element model was also updated upon the changes in thickness and density of the truncated cones, and consequently, comparison between the theoretical and experimental natural frequencies was carried out again. Also, micrographs of two truncated cones were taken before and after autoclave treatment to examine the autoclave effect on the quality of the samples.

scholarly journals Effect of compaction roller on layup quality and defects formation in automated fiber placement

2019 ◽  
Vol 39 (1-2) ◽  
pp. 3-20 ◽  
Author(s):  
Nima Bakhshi ◽  
Mehdi Hojjati
Keyword(s):  
Experimental Study ◽  
Finite Element ◽  
Pressure Distribution ◽  
Finite Element Simulations ◽  
Process Conditions ◽  
Fiber Placement ◽  
Static Testing ◽  
Contact Width ◽  
Automated Fiber Placement

Application of automated fiber placement is limited by defects formed in the prepreg tows during the layup process. An extensive experimental study is performed to investigate the effect of compaction roller on the quality of the layup. Five different compaction rollers with different stiffness and architectures were manufactured and employed to dispense prepreg tows at various process conditions. Layup quality was examined and different defects including tow buckling and blister were identified. In addition to automated fiber placement trials, static testing and finite element simulations were performed to probe the pressure distribution and contact width of each roller. This data was used to support and understand the results of the automated fiber placement trials. Results indicate the solid elastomer rollers that are compliant enough to produce the same level of contact width under similar levels of compaction forces are superior to the perforated rollers in terms of achievable layup quality.

Modal Analysis and Optimization of Spindle Box of Turn-Milling Center Based on Finite Element Method

2012 ◽  
Vol 226-228 ◽  
pp. 281-284
Author(s):  
Li Da Zhu ◽  
Xiao Bang Wang ◽  
Tiao Biao Yu ◽  
Wan Shan Wang
Keyword(s):  
Finite Element ◽  
Natural Frequencies ◽  
Element Model ◽  
Ansys Software ◽  
Design Requirement ◽  
Design Quality ◽  
Machining Center ◽  
Main Components ◽  
Turn Milling

The dynamic characteristics of machine tool may directly affect its machining capability, which is analyzed to improve the machining precision and efficiency. In this paper, the 3D finite element model of main components turn-milling center is established by using ANSYS software, and then spindle box of turn-milling center is analyzed and optimized; the natural frequencies and vibration models are obtained after analysis, which guarantee the design requirement of the machining center. Therefore it is significant to improve the design quality of machining center by using FEA software in the design process.

scholarly journals Dynamics Characteristics of Blast Furnace Shell

2011 ◽  
Vol 2-3 ◽  
pp. 1018-1020
Author(s):  
De Chen Zhang ◽  
Yan Ping Sun
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Blast Furnace ◽  
Modal Analysis ◽  
Natural Frequencies ◽  
Theoretical Foundation ◽  
Structural Mechanics ◽  
Mode Shapes ◽  
The Future ◽  
Element Method

Finite element method and structural mechanics method are used to study the blast furnace shell modal analysis and the natural frequencies and mode shapes have been calculated. The two methods were compared and validated , and the results provide a theoretical foundation for the anti-vibration capabilities design of blast furnace shell in the future .

Experimental Identification Approach of Dynamic Parameters of Precise Horizontal Machining Centre Based on Component-System

2011 ◽  
Vol 467-469 ◽  
pp. 1686-1690
Author(s):  
Zhi Feng Liu ◽  
Zhong Hua Chu ◽  
Qiang Cheng ◽  
Guang Bo Liu ◽  
Dong Sheng Xuan
Keyword(s):  
Finite Element ◽  
Modal Analysis ◽  
Natural Frequencies ◽  
Modal Testing ◽  
Element Calculation ◽  
Element Simulation ◽  
Modes Of Vibration ◽  
Identification Approach ◽  
Comparison Of The Results ◽  
Machine Structure

This paper integrates experiment modal analysis and the analytical modal analysis to study on the vibration phenomena occurring occasionally at the different components of a precise horizontal machining centre. The paper is focused on extracting the mode shape of the major components of the machine in order to ensure resonance phenomena as a cause of vibration. At first the main natural frequencies with the corresponding modes of vibration of the machine structure are obtained by the experiment modal analysis. Then the dynamic behavior of the machine components is simulated using a finite element simulation model. The comparison of the results based on finite element calculation with their experimental counterparts shows the reasonableness. The model is evaluated and corrected with experimental results by modal testing of the machine components.

scholarly journals Simulation of laser heating distribution for a thermoplastic composite: effects of AFP head parameters

2020 ◽  
Vol 110 (7-8) ◽  
pp. 2105-2117
Author(s):  
Omar Baho ◽  
Gilles Ausias ◽  
Yves Grohens ◽  
Julien Férec
Keyword(s):  
Laser Beam ◽  
Laser Heating ◽  
Thermal Model ◽  
Laser Energy ◽  
Thermoplastic Composite ◽  
Thermoplastic Composites ◽  
Efficient Production ◽  
Fiber Placement ◽  
Aerospace Applications ◽  
Automated Fiber Placement

Abstract Laser-assisted automated fiber placement (AFP) is highly suitable for an efficient production of thermoplastic-matrix composite parts, especially for aeronautic/aerospace applications. Heat input by laser heating provides many advantages such as better temperature controls and uniform heating projections. However, this laser beam distribution can be affected by the AFP head system, mainly at the roller level. In this paper, a new optico-thermal model is established to evaluate the laser energy quantity absorbed by a poly(ether ether ketone) reinforced with carbon fibers (APC-2). During the simulation process, the illuminated radiative material properties are characterized and evaluated in terms of the roller deformation, the tilt of the robot head, and the reflection phenomenon between the substrate and the incoming tape. After computing the radiative source term using a ray-tracing method, these data are used to predict the temperature distribution on both heated surfaces of the composite during the process. The results show that both the roller deformation and the tilt of head make it possible to focus the laser beam on a small area, which considerably affects the quality of the finished part. These findings demonstrate that this optico-thermal model can be used to predict numerically the insufficient heating area and thermoplastic composites heating law.

Modal Analysis of Flexible Assembling Fixture for Aircraft Panel Component

2010 ◽  
Vol 97-101 ◽  
pp. 3392-3396
Author(s):  
Li Gang Qu ◽  
Ke Qiang Pan ◽  
Xin Chen
Keyword(s):  
Finite Element ◽  
Modal Analysis ◽  
Dynamic Characteristic ◽  
Natural Frequencies ◽  
Great Influence ◽  
Vibration Characteristics ◽  
Mode Shapes ◽  
Dynamic Vibration ◽  
Structural Weakness ◽  
Modal Vibration

The dynamic characteristic of flexible assembling fixture (FAF) for aircraft panel component is analysed by the method of finite element modal analysis. Consequently, the every order of natural frequencies and mode shapes of given different postures of the FAF are obtained. It structural weakness were pointed out through the analysis results of the modal vibration characteristics. The properties of mass and stiffness of the FAF's components are concurrently calculated, whose optimal matching and harmonizing with each other have great influence on the dynamic vibration characteristics of the FAF. As the results of these analysis, the design improving suggestion for the FAF is put forward.

Impact of layup rate on the quality of fiber steering/cut-restart in automated fiber placement processes

2015 ◽  
Vol 22 (2) ◽  
pp. 165-173 ◽  
Author(s):  
Jihua Chen ◽  
Teresa Chen-Keat ◽  
Mehdi Hojjati ◽  
AJ Vallee ◽  
Marc-Andre Octeau ◽  
...  
Keyword(s):  
Compaction Pressure ◽  
Experimental Studies ◽  
Process Condition ◽  
Processing Parameters ◽  
Experimental Results ◽  
High Quality ◽  
Fiber Placement ◽  
Automated Fiber Placement

AbstractDeveloping reliable processes is one of the key elements in producing high-quality composite components using an automated fiber placement (AFP) process. In this study, both simulation and experimental studies were carried out to investigate fiber steering and cut/restart under different processing parameters, such as layup rate and compaction pressure, during the AFP process. First, fiber paths were designed using curved fiber axes with different radii. Fiber placement trials were then conducted to investigate the quality of the steered fiber paths. Furthermore, a series of sinusoidal fiber paths were fiber placed and investigated. Moreover, a six-ply laminate with cut-outs in it was manufactured in the cut/restart trials. The accuracy of the fiber cut/restart was compared at different layup rates for both one- and bi-directional layups. Experimental results show that it was possible to layup steered fiber paths with small radii of curvature (minimum 114 mm) designed for this study when the proper process condition was used. It was observed from the cut/restart trials that the quality of tow cut was independent of layup speed; however, the accuracy of tow restart was related to the layup speed. The faster the layup speed, the less accurate was the tow restart.

Parametric Design and Modal Analysis on Four-Order Elliptical Gear

2013 ◽  
Vol 423-426 ◽  
pp. 1516-1519
Author(s):  
Zhi Dong Huang ◽  
An Min Hui ◽  
Guang Yang ◽  
Rui Yang Li
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Dynamic Response ◽  
Modal Analysis ◽  
Dynamic Model ◽  
Natural Frequencies ◽  
Parametric Design ◽  
Three Dimensional ◽  
Response Analysis ◽  
Dynamic Design

The characteristics of four-order elliptical gear is analyzed. The parameters of four-order elliptical gear are chosen and calculated. The three-dimensional solid modeling of four-order elliptical gear is achieved. The dynamic model of four-order elliptical gear is established by finite element method and modal analysis of four-order elliptical gear is investigated. The natural frequencies and major modes of the first six orders are clarified. The method and the result facilitate the dynamic design and dynamic response analysis of high-order elliptical gear.

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