scholarly journals Experimental study of the effect of automated fiber placement induced defects on performance of composite laminates

2011 ◽  
Vol 42 (5) ◽  
pp. 484-491 ◽  
Author(s):  
Kaven Croft ◽  
Larry Lessard ◽  
Damiano Pasini ◽  
Mehdi Hojjati ◽  
Jihua Chen ◽  
...  
Keyword(s):  
Experimental Study ◽  
Composite Laminates ◽  
Fiber Placement ◽  
Automated Fiber Placement ◽  
Induced Defects

scholarly journals Experimental Investigation on the Influence of Fiber Path Curvature on the Mechanical Properties of Composites

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2602
Author(s):  
Huaqiao Wang ◽  
Jihong Chen ◽  
Zhichao Fan ◽  
Jun Xiao ◽  
Xianfeng Wang
Keyword(s):  
Tensile Strength ◽  
Path Planning ◽  
Composite Laminates ◽  
Bending Strength ◽  
High Strength ◽  
Bending Test ◽  
Fiber Placement ◽  
Automated Fiber Placement ◽  
Fiber Path ◽  
Path Curvature

Automated fiber placement (AFP) has been widely used as an advanced manufacturing technology for large and complex composite parts and the trajectory planning of the laying path is the primary task of AFP technology. Proposed in this paper is an experimental study on the effect of several different path planning placements on the mechanical behavior of laminated materials. The prepreg selected for the experiment was high-strength toughened epoxy resin T300 carbon fiber prepreg UH3033-150. The composite laminates with variable angles were prepared by an eight-tow seven-axis linkage laying machine. After the curing process, the composite laminates were conducted by tensile and bending test separately. The test results show that there exists an optimal planning path among these for which the tensile strength of the laminated specimens decreases slightly by only 3.889%, while the bending strength increases greatly by 16.68%. It can be found that for the specific planning path placement, the bending strength of the composite laminates is significantly improved regardless of the little difference in tensile strength, which shows the importance of path planning and this may be used as a guideline for future AFP process.

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.

Experimental and numerical investigation of the effect of gaps on fatigue behavior of unidirectional carbon/epoxy automated fiber placement laminates

2016 ◽  
Vol 51 (6) ◽  
pp. 759-772 ◽  
Author(s):  
Yasser Mahmoud Elsherbini ◽  
Suong V Hoa
Keyword(s):  
Fatigue Life ◽  
Applied Stress ◽  
Fatigue Behavior ◽  
Damage Model ◽  
Fatigue Loading ◽  
Fatigue Tests ◽  
Experimental Results ◽  
Fiber Placement ◽  
Automated Fiber Placement ◽  
Induced Defects

Automated fiber placement (AFP) process provides high potential to repeatability and flexibility required for manufacturing of complex parts in many industries. Performance of such parts can be influenced by AFP manufacturing induced defects such as gaps and overlaps. In this work, the effect of gaps on fatigue behavior of unidirectional carbon/epoxy laminates was investigated. Tension–tension fatigue tests were conducted on defected samples and compared to reference samples free from defects. Infrared thermography technique was used for monitoring of damage propagation during fatigue loading. Moreover, a fatigue progressive damage model (FPDM) was developed and applied to laminates containing gaps to predict fatigue damage progression and failure. The experimental results revealed that the effect of gaps depends on the maximum applied stress during fatigue. The higher is the applied stress, the higher is the reduction in fatigue life. Good agreement was found between the results of fatigue life prediction from the FPDM and the experimental results for defected specimens.

Induced defect layer method to characterize the effect of fiber tow gaps for the laminates manufactured by automated fiber placement technique

2021 ◽  
pp. 002199832110316
Author(s):  
Mohammadhossein Ghayour ◽  
Mehdi Hojjati ◽  
Rajamohan Ganesan
Keyword(s):  
Composite Laminates ◽  
Composite Structures ◽  
Structural Integrity ◽  
Mechanical Response ◽  
Defect Layer ◽  
Damage Analysis ◽  
Manufacturing Defects ◽  
Fiber Placement ◽  
Layer Method ◽  
Automated Fiber Placement

Automated manufacturing defects are new types of composite structure defects induced during fiber deposition by robots. Fiber tow gap is one of the most probable types of defects observed in the Automated Fiber Placement (AFP) technique. This defect can affect the structural integrity of structures by reducing structural strength and stiffness. The effect of this defect on the mechanical response of the composite laminates has been investigated experimentally in the literature. However, there is still no efficient numerical/analytical method for damage assessment of composite structures with distributed induced gaps manufactured by the AFP technique. The present paper aims to develop the Induced Defect Layer Method (IDLM), a new robust meso-macro model for damage analysis of the composite laminates with gaps. In this method, a geometrical parameter, Gap Percentage (GP), is implemented to incorporate the effect of induced-gaps in the elastic, inelastic, and softening behavior at the material points. Thus, while the plasticity and failure of the resin pockets in conjunction with intralaminar composite damages can be evaluated by this method, the defective areas are not required to be defined as resin elements in the Finite Element (FE) models. It can also be applied for any arbitrary distributions of the defects in the multi-layer composite structures, making it a powerful tool for continuum damage analysis of large composite structures. Results indicate that the proposed method can consider the effect of gaps in both elastic and inelastic behavior of the composite laminate with defects. It also provides good agreement with the experimental results.

scholarly journals Experimental Study of the Effect of Internal Defects on Stress Waves during Automated Fiber Placement

Polymers ◽  
2018 ◽  
Vol 10 (4) ◽  
pp. 413 ◽  
Author(s):  
Zhenyu Han ◽  
Shouzheng Sun ◽  
Wenqi Li ◽  
Yaoxu Zhao ◽  
Zhongxi Shao
Keyword(s):  
Experimental Study ◽  
Stress Waves ◽  
Internal Defects ◽  
Fiber Placement ◽  
Automated Fiber Placement

Experimental and numerical investigation on the open-hole compressive strength of AFP composites containing gaps and overlaps

2017 ◽  
Vol 51 (26) ◽  
pp. 3631-3646 ◽  
Author(s):  
Aymen Marouene ◽  
Pierre Legay ◽  
Rachid Boukhili
Keyword(s):  
Compression Strength ◽  
Composite Laminates ◽  
Composite Structures ◽  
Progressive Failure ◽  
Experimental Tests ◽  
Consolidation Process ◽  
Fiber Placement ◽  
Positive Effects ◽  
Open Hole ◽  
Automated Fiber Placement

Laminated composite structures manufactured via the automated fiber placement process inherently contain process defects know as gaps and overlaps. These defects raise concerns when they are located on or near holes intended for mechanical fastening. This investigation attempts to predict the effect of automated fiber placement-generated defects on the open-hole compression strength by combining both experimental tests and numerical simulation. Tested open-hole compression specimens containing gaps and overlaps oriented at 0° or 90° and centered on or shifted near the hole show that, depending on their location, the gaps and overlaps may have negative, negligible, or positive effects on the open-hole compression strength. The better than expected effects are compatible with microscopic observations that clearly show the rearrangement of the plies during the consolidation process, which prevent the formation of deleterious discontinuities. Incorporating these observations in a numerical model, which simulates gaps and overlaps embedded inside the composite laminates, and applying a progressive failure analysis, confirms that the effects of automated fiber placement defects depend as much on their type as on their location relative to the hole center. Finally, the results obtained from a parametric study provided further explanation on the effects of automated fiber placement defects on the failure strength of perforated composite laminates.

Effect of the attitude fine-adjustment of compaction roller on automated fiber placement defects and trajectory

2019 ◽  
Vol 38 (12) ◽  
pp. 539-555 ◽  
Author(s):  
Jinxiang Cheng ◽  
Dongbiao Zhao ◽  
Huaiyuan Chen ◽  
Yingru Zhang ◽  
Yangwei Wang
Keyword(s):  
Differential Geometry ◽  
Roll Angle ◽  
Processing Quality ◽  
Fiber Waviness ◽  
Fiber Placement ◽  
Automated Fiber Placement ◽  
Series Of Experiments ◽  
Yaw Angle ◽  
Induced Defects ◽  
Fine Adjustment

Automated fiber placement shows great potential for fabricating complex aircraft structures. During AFP process, the process-induced defects and placement trajectory have important effect on the processing quality. These defects and trajectory are influenced by many factors, where the attitude of compaction roller is an important factor. By the attitude fine-adjustment of compaction roller, the placement defects and trajectory can be improved. It is necessary to study the effect of the attitude fine-adjustment of compaction roller on placement defects and trajectory. The attitude includes yaw and roll of compaction roller, and the placement defects mainly refer to the fitness degree and fiber pull-up. Firstly, the placement ability of compaction roller is defined by making full use of the allowable distance. Then, the yaw angle and position of compaction roller are calculated by differential geometry. Meanwhile, the yaw distance and placement width are given. Secondly, the fiber pull-up is defined and described as planar sinusoidal based on the fiber waviness theory. Then the roll angle and position of compaction roller are given. Finally, a series of experiments and simulations had been conducted to verify the feasibility of the developed method. Results demonstrate that the method can improve the placement defects and trajectory.

Sign in / Sign up

Export Citation Format

Share Document