Impact-Induced Damage Progression in 2-D and 3-D Woven Composite Systems

2001 ◽  
Author(s):  
Jared N. Baucom ◽  
Mohammed A. Zikry
Keyword(s):  
Failure Modes ◽  
Surface Condition ◽  
Woven Composites ◽  
Woven Composite ◽  
Additional Energy ◽  
3 Dimensional ◽  
Damage Progression ◽  
Glass Fiber Reinforced ◽  
The Difference ◽  
The Impact

Abstract The role of fabric architecture on the impact-induced damage progression and perforation resistance of glass-fiber reinforced vinyl-ester resin panels under dynamic loading condition is investigated. Three fabric preforms are considered: a 2-dimensional, plain-woven laminate, a commercially available biaxially reinforced warp-knit, and a 3-dimensional, orthogonally woven preform. Composite samples are subjected to multiple impacts, until perforation, and the impactor position and acceleration are monitored throughout each event, resulting in a visualization of dynamic energy dissipation. Failure modes of the various material systems are characterized. The radial damage expansion was smallest for the 2-d laminate, larger for the biaxially-reinforced warp-knit, and largest for the 3-d orthogonal woven composite. The 3-d composite survived more hits and dissipated more total energy than the other systems. The difference may be due to the additional energy absorption mechanisms, which involve the crimped portion of z-tows in the 3-d composites. This implies that failure may be controlled by manipulation of the properties of the z-tows. It also indicates that the surface condition of 3-d orthogonally woven composites can strongly affect the progression of impact-induced damage.

Deformation Fields in Woven Composite Plates Under Impact

2002 ◽  
Author(s):  
Y. A. Bahei-El-Din ◽  
M. A. Zikry ◽  
A. Rajendran
Keyword(s):  
Structural Parameters ◽  
Composite Plates ◽  
Dynamic Contact ◽  
Element Model ◽  
Cellular Systems ◽  
Woven Composites ◽  
Porous System ◽  
Woven Composite ◽  
Dynamic Contact Problem ◽  
The Impact

The deformation fields and kinematics of woven composite material systems due to impact loads are analyzed and characterized for various structural parameters. Target plates comprised of woven composites with 3D preforms are considered. The analysis examines fully consolidated as well as cellular systems and simulates actual experiments. Solution of the nonlinear dynamic/contact problem was obtained by a meso-mechanics based finite element model. The results quantify experimental observations, which reveal distinct behavior under impact among nonporous and porous systems. It was found that wave propagation effects at incident energies in the order of 500 J are significant and lead to penetration at the impact face. Localized shear damage in the 3D woven system precede penetration in both the nonporous and the porous systems. The porous system is capable of dissipating more energy prior to penetration due to containment of local damage, which emanates from the void boundaries, within subsurface locations.

A progressive damage model for 3D woven composites under compression

2018 ◽  
Vol 28 (6) ◽  
pp. 857-876 ◽  
Author(s):  
Huaiyu Lu ◽  
Licheng Guo ◽  
Gang Liu ◽  
Li Zhang
Keyword(s):  
Failure Modes ◽  
Damage Model ◽  
Woven Composites ◽  
Progressive Damage ◽  
Misalignment Angle ◽  
Woven Composite ◽  
Damage Initiation ◽  
3D Woven Composites ◽  
Progressive Damage Model ◽  
Transverse Failure

A progressive damage model is proposed to investigate the damage initiation and evolution of 3D woven composites under uniaxial compression at a micromechanical level. The typical compressive experiments were carried out. Based on the observations, the compression failure modes of 3D woven composites mainly include fiber kinking, transverse failure of fiber tow, matrix fracture, and interfacial debonding. The initial damage criteria are according to the physically based failure criteria for the fiber kinking, the Puck criteria for the transverse failure of fiber tow, and the maximum stress criterion for the matrix. The damage of fiber tow–matrix interfacial is simulated through cohesive contact. Particularly, the fiber’s initial misalignment angle is taken into account in the damage model. The simulated compression results agree well with the experimental ones. The compressive stress–strain response of the 3D woven composite is forecasted. The damage evolution of each constituent of the 3D woven composite is obtained. The results show that the influence of the fiber’s initial misalignment angle on the compression strength of the 3D woven composite needs to be considered.

Impact performances and failure modes of glass fiber reinforced polymers in different curvatures and stacking sequences

2021 ◽  
pp. 002199832110590
Author(s):  
Cihan Kaboglu ◽  
Taha Y Eken ◽  
Yakup Yurekturk
Keyword(s):  
Glass Fiber ◽  
Failure Modes ◽  
Impact Resistance ◽  
Matrix Cracking ◽  
Fiber Reinforced ◽  
Stacking Order ◽  
Glass Fiber Reinforced ◽  
The Impact

Recently, glass fiber reinforced polymer composites have been increasingly used in applications which are exposed to impact loads due to their high strength, low weight, and corrosion resistance properties. Therefore, the effect of curvature of composite laminate on their impact resistance is important. In this study, the mechanical properties of three curvature diameters and two stacking sequences, which have not been compared before, were examined and compared. The diameter of curved composites is 760 mm, 380 mm, and 304 mm and flat designated as A, B, C, and D, respectively. The fiber stacking orders are [0/0/-45/+45/90/90]S and [90/90/-45/+45/0/0]S designated as Type 1 and Type 2, respectively. The drop-weight impact tests were performed and failure modes of composites were examined. It was observed that the impact resistance decreases with the increase of curvature, where 760 mm diameter and Type 2 composites had the highest strength in all of the composites. In addition, delamination, fiber breakage, and matrix cracking failure modes were observed in the composites after impact. The reason why the strength decreases as the curvature of the composite increases is that the curved areas create an effect that increases the external force applied. The reason why Type 2 stacking order is more durable than Type 1 stacking order is that the 90° fiber direction in the bottom layer has a damping effect on the applied force. According to the results of this study, composite materials with larger diameter and stacking order starting with 0° provides more mechanical strength. [Formula: see text]

Crush Force Efficiency of Composite Square Profile under Off-Axis Loading

2013 ◽  
Vol 594-595 ◽  
pp. 711-714
Author(s):  
A.A. Arifin ◽  
A. Othman
Keyword(s):  
Cross Section ◽  
Static Loading ◽  
Failure Modes ◽  
Polyester Resin ◽  
Peak Load ◽  
Woven Composite ◽  
Laminate Glass ◽  
Number Of Layers ◽  
Glass Fiber Reinforced ◽  
Initial Peak

The present paper determines the effect of crush force efficiency on laminate glass wrapped on aluminum cross-section square tubes under quasi-static loading. The analysis was examined via experimentally. The wall-thicknesses aluminum square of 1.6 mm was investigated on wrapped woven composite type of E-glass fiber reinforced polyester resin. Two different numbers of layers woven E-glass were investigated and examined. Result obtained from experimental analysis such that initial peak load, mean load, versus displacement curves were compared for each specimen. Results showed that the tubes energy absorption was affected significantly by different number of layers wrapped on wall aluminum square profile and also that the effect of crushing behaviors and failure modes was discussed.

scholarly journals Impact Resistance of 3D Woven Composites Impacted by Different Impactor Shapes

2019 ◽  
Vol 7 (4.14) ◽  
pp. 449
Author(s):  
D. P.C. Aiman ◽  
M. F. Yahya ◽  
M. R. Ahmad ◽  
S. A. Ghani
Keyword(s):  
Impact Test ◽  
Impact Resistance ◽  
Woven Fabric ◽  
Woven Composites ◽  
Woven Composite ◽  
Fabric Composite ◽  
3D Woven Composites ◽  
Set Up ◽  
The Impact ◽  
Composite Samples

The aim of this study was to investigate impact resistance of 3D woven composites, impacted by three different impactor shapes. An experimental study was carried out to compare the impact resistance on four types of 3D woven fiberglass composites. Impact resistance test will be performed using standard method ASTM D2444, with a set up initial impact energy is 20 J, velocity of 3.4901 m/s, height of 0.6163m and mass applied is 3.29 kg. Three different impactor shapes which are hemispherical, conical and ogival were used for testing woven fabric composite impact test. Hand lay-up technique was used to fabricate the composites. From results, 4 float Layer-to-layer Interlock (4L) gave the highest impact resistance for all impactor shapes with 6258.0 N for hemispherical impactor, 4000.1 N for conical impactor and 3750.7 N for ogival impactor. Ogival impactor tends to penetrate the woven composite samples better compared to conical and hemispherical impactors. 

Experimental Investigation on the Low-Velocity Impact Damage of 3D Angle-Interlock Woven Composites

2012 ◽  
Vol 487 ◽  
pp. 793-797 ◽  
Author(s):  
Li Juan Yu ◽  
Li Min Jin ◽  
Zhi Lin Niu ◽  
Bao Zhong Sun ◽  
Yi Zhu Zheng ◽  
...  
Keyword(s):  
Failure Modes ◽  
Shear Failure ◽  
Impact Damage ◽  
Low Velocity Impact ◽  
Impact Behavior ◽  
Woven Composites ◽  
Low Velocity ◽  
Plane Shear ◽  
Velocity Impact ◽  
The Impact

In this paper, the low-velocity impact behavior of the 3D angle-interlock woven glass-fiber/epoxy composites (3DAWCs) were tested and analyzed under several levels of impact energies. The energy-time curves, deflection-time curves and load-deflection curves were obtained to show the impact damage behavior. It was found that the damage magnitude increases with the impact energy, and the composite structure can effectively reduce the in-plane shear failure. In addition, the failure modes were also photographed to illustrate the damage mechanisms of the3DAWCs.

Evaluation of the impact of public investment programs on social and economic performance of territories

2019 ◽  
pp. 109-123
Author(s):  
I. E. Limonov ◽  
M. V. Nesena
Keyword(s):  
Bayesian Modeling ◽  
Positive Impact ◽  
Public Investment ◽  
Difference In Differences ◽  
The Public ◽  
Export Activity ◽  
Regional Investment ◽  
The Difference ◽  
The Impact ◽  
Development Institution

The purpose of this study is to evaluate the impact of public investment programs on the socio-economic development of territories. As a case, the federal target programs for the development of regions and investment programs of the financial development institution — Vnesheconombank, designed to solve the problems of regional development are considered. The impact of the public interventions were evaluated by the “difference in differences” method using Bayesian modeling. The results of the evaluation suggest the positive impact of federal target programs on the total factor productivity of regions and on innovation; and that regional investment programs of Vnesheconombank are improving the export activity. All of the investments considered are likely to have contributed to the reduction of unemployment, but their implementation has been accompanied by an increase in social inequality.

The Use of Multimedia and its Impact on Bangladeshi EFL Learners at Tertiary Level

2020 ◽  
Vol 4 (2) ◽  
pp. 150
Author(s):  
Farzana Sharmin Pamela Islam
Keyword(s):  
Language Learning ◽  
Academic Writing ◽  
Teaching And Learning ◽  
English Language ◽  
Capital City ◽  
Tertiary Level ◽  
Language Classroom ◽  
The Difference ◽  
The Government ◽  
The Impact

As 21st century is the era of modern technologies with different aspects, it offers us to make the best use of them. After tape recorder and overhead projector (OHP), multimedia has become an important part of language classroom facilities for its unique and effective application in delivering and learning lesson. Although in many parts of Bangladesh, a South Asian developing country, where English enjoys the status of a foreign language, the use of multimedia in teaching and learning is viewed as a matter of luxury. However, nowadays the usefulness and the necessity of it are well recognized by the academics as well as the government. The study aims to focus on the difference between a traditional classroom void of multimedia and multimedia equipped classrooms at university level by explaining how multimedia support the students with enhanced opportunity to interact with diverse texts that give them more in-depth comprehension of the subject. It also focuses on audio-visual advantage of multimedia on the students’ English language learning. The study has followed a qualitative method to get an in-depth understanding of the impact of using multimedia in an English language classroom at tertiary level. For this purpose, the data have been collected from two different sources. Firstly, from students’ written response to  an open ended question as to their comparative experience of learning  lessons with and without multimedia facilities; and secondly, through  observation of English language classes at a private university of Dhaka, the capital city of Bangladesh. The discussion of the study is limited to  the use of multimedia in English language classroom using cartoons, images and music with a view to enhance students’ skills in academic writing, critical analysis of image and critical appreciation of music. For this purpose, cartoons in English language, images from Google and music from You Tube have got focused discussion in this paper.

Case study: Prediction and field tests of railway noise and effects of a low-height noise barrier

2020 ◽  
Vol 68 (4) ◽  
pp. 303-314
Author(s):  
Yuna Park ◽  
Hyo-In Koh ◽  
University of Science and Technology, Transpo ◽  
University of Science and Technology, Transpo ◽  
University of Science and Technology, Transpo ◽  
...  
Keyword(s):  
High Speed ◽  
Field Tests ◽  
Residential Areas ◽  
Railway Systems ◽  
Railway Noise ◽  
Sound Levels ◽  
Noise Barrier ◽  
The Difference ◽  
Reduction Effect ◽  
The Impact

Railway noise is calculated to predict the impact of new or reconstructed railway tracks on nearby residential areas. The results are used to prepare adequate counter- measures, and the calculation results are directly related to the cost of the action plans. The calculated values were used to produce noise maps for each area of inter- est. The Schall 03 2012 is one of the most frequently used methods for the production of noise maps. The latest version was released in 2012 and uses various input para- meters associated with the latest rail vehicles and track systems in Germany. This version has not been sufficiently used in South Korea, and there is a lack of standard guidelines and a precise manual for Korean railway systems. Thus, it is not clear what input parameters will match specific local cases. This study investigates the modeling procedure for Korean railway systems and the differences between calcu- lated railway sound levels and measured values obtained using the Schall 03 2012 model. Depending on the location of sound receivers, the difference between the cal- culated and measured values was within approximately 4 dB for various train types. In the case of high-speed trains, the value was approximately 7 dB. A noise-reducing measure was also modeled. The noise reduction effect of a low-height noise barrier system was predicted and evaluated for operating railway sites within the frame- work of a national research project in Korea. The comparison of calculated and measured values showed differences within 2.5 dB.

scholarly journals Soil Moisture Dynamics in Response to Precipitation and Thinning in a Semi-Dry Forest in Northern Mexico

Water ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 105
Author(s):  
Argelia E. Rascón-Ramos ◽  
Martín Martínez-Salvador ◽  
Gabriel Sosa-Pérez ◽  
Federico Villarreal-Guerrero ◽  
Alfredo Pinedo-Alvarez ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Forest Management ◽  
Water Availability ◽  
Dry Forest ◽  
Rainfall Events ◽  
Rainfall Characteristics ◽  
Northern Mexico ◽  
The Difference ◽  
The Impact ◽  
Moisture Dynamics

Understanding soil moisture behavior in semi-dry forests is essential for evaluating the impact of forest management on water availability. The objective of the study was to analyze soil moisture based in storm observations in three micro-catchments (0.19, 0.20, and 0.27 ha) with similar tree densities, and subject to different thinning intensities in a semi-dry forest in Chihuahua, Mexico. Vegetation, soil characteristics, precipitation, and volumetric water content were measured before thinning (2018), and after 0%, 40%, and 80% thinning for each micro-catchment (2019). Soil moisture was low and relatively similar among the three micro-catchments in 2018 (mean = 8.5%), and only large rainfall events (>30 mm) increased soil moisture significantly (29–52%). After thinning, soil moisture was higher and significantly different among the micro-catchments only during small rainfall events (<10 mm), while a difference was not noted during large events. The difference before–after during small rainfall events was not significant for the control (0% thinning); whereas 40% and 80% thinning increased soil moisture significantly by 40% and 53%, respectively. Knowledge of the response of soil moisture as a result of thinning and rainfall characteristics has important implications, especially for evaluating the impact of forest management on water availability.

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