scholarly journals Studies on the Geometrical Design of Spider Webs for Reinforced Composite Structures

2021 ◽  
Vol 5 (2) ◽  
pp. 57
Author(s):  
Yohannes Regassa ◽  
Hirpa G. Lemu ◽  
Belete Sirabizuh ◽  
Samuel Rahimeto
Keyword(s):  
Fiber Orientation ◽  
Composite Structures ◽  
Spider Silk ◽  
Pressure Vessels ◽  
Aviation Industry ◽  
Measurement Tool ◽  
Spider Webs ◽  
Spider Web ◽  
Reinforced Composite ◽  
Structural Applications

Spider silk is an astonishingly tough biomaterial that consists almost entirely of large proteins. Studying the secrets behind the high strength nature of spider webs is very challenging due to their miniature size. In spite of their complex nature, researchers have always been inspired to mimic Nature for developing new products or enhancing the performance of existing technologies. Accordingly, the spider web can be taken as a model for optimal fiber orientation for composite materials to be used in critical structural applications. In this study an attempt is made to analyze the geometrical characteristics of the web construction building units such as spirals and radials. As a measurement tool, we have used a developed MATLAB algorithm code for measuring the node to node of rings and radials angle of orientation. Spider web image samples were collected randomly from an ecological niche with black background sample collection tools. The study shows that the radial angle of orientation is 12.7 degrees with 5 mm distance for the spirals’ mesh size. The extracted geometrical numeric values from the spider web show moderately skewed statistical data. The study sheds light on spider web utilization to develop an optimized fiber orientation reinforced composite structure for constructing, for instance, shell structures, pressure vessels and fuselage cones for the aviation industry.

scholarly journals Investigation of spider web oriented composite fabrics burst strength

2021 ◽  
Vol 8 (4) ◽  
pp. 622-639
Author(s):  
Yohannes Regassa ◽  
◽  
Hirpa G. Lemu ◽  
Belete Sirhabizu ◽  
Keyword(s):  
Fiber Orientation ◽  
Composite Structures ◽  
Burst Strength ◽  
Spider Web ◽  
Reinforced Composite ◽  
Significant Step ◽  
Orientation Technique ◽  
Composite Product ◽  
Research Gap ◽  
Composite Fabrics

<abstract> <p>Burst strength is a significant property that determines all other properties of structures to perform under induced internal pressure. In this study, the burst strength of a spider web-formed fabric structure is experimentally investigated. The spider web form orientation is prepared using Embroidery machine. A spider web develops a self-stressing nature, which offers its excellent inelasticity and provides a mechanism for competent and economical means to harmonize the local and global induced stresses in their structure. The obtained results are compared with published works on different effects of fiber architectures. The burst test result on spider web form indicated a spider web form's potential candidacy to utilize it as a future fiber orientation technique to form an enhanced composite reinforcement. However, fiber orientation influences the fiber-reinforced composite's mechanical properties. Fiber orientation via spider web form has not yet been used as a reinforcing engineering composite product. Hence, conducting rigors experimental work on spider web form reinforced composite structures can be taken as a significant step to fill the research gap.</p> </abstract>

A Novel Assessment Method for Wrinkle Defects in Composites

2020 ◽  
Author(s):  
Chuanchuan Shen ◽  
Li Ma ◽  
Jinyang Zheng
Keyword(s):  
Composite Structures ◽  
Tensile Load ◽  
Pressure Vessels ◽  
Curing Temperature ◽  
Transverse Compression ◽  
Fiber Reinforced ◽  
Displacement Fields ◽  
Fiber Reinforced Composite ◽  
Reinforced Composite ◽  
Environment Temperature

Abstract Fiber reinforced composite structures have been increasingly used in the field of pressure vessels and piping. Various process-induced defects of composite structures are accumulated during their manufacture processes for the variations of environment temperature and humidity, pre-stress of fiber and curing temperature. Wrinkle defect is one of the most frequently encountered defects in fiber reinforced composite structures. In this paper, a new method for detecting wrinkle defects based on the relation of the displacement fields between flawed and flawless areas is proposed. The orthotropic finite element analysis codes combined with wrinkle model were developed based on Matlab platform to predict structural responses of laminates under three different loading types, including transverse compression, axial tension and bending. The effective elastic moduli disturbed by wrinkles were determined based on a mesomechanics model and a two-step homogenization procedure. Two different wrinkle models including definite and heterogeneous distributed models were considered. It is found that the out-of-plane displacement obviously increases at the wrinkle region under the axial load. The fluctuant displacement fields under axial tensile load can be clearly observed when the heterogeneity wrinkle model is considered. However, the transverse compression cannot produce any displacement distortion. All the results bring us a new idea of non-destructive evaluation for composites, wherein the defects that mainly weakening the stiffness can be detected by measuring the displacement distribution under some specified loads.

Stress and Damage Analysis of Fiber-Reinforced Composite Pipe

2018 ◽  
Author(s):  
I. Ramos ◽  
Y. H. Park ◽  
J. Ulibarri-Sanchez
Keyword(s):  
Fatigue Behavior ◽  
Weight Ratio ◽  
High Strength ◽  
Pressure Vessels ◽  
Damage Analysis ◽  
Fiber Reinforced ◽  
Reinforced Composite ◽  
Structural Applications ◽  
Fuel Tanks ◽  
Failure Conditions

Composite materials are used in many environments due to their special properties such as high strength-to-weight ratio, corrosion resistance and the ability to be tailored to specific requirements. In particular, the use of fiber reinforced composites (FRCs) for pressure vessels/pipes has increased in structural applications such as fuel tanks, pipes, vessels, and rocket motor cases. Assessing failure conditions is important to ensure that these structures do not fail under their operating condition. In this study, an analytical procedure is developed to predict the fatigue behavior of FRC. A numerical model will also be developed and applied to failure analysis under internal pressure loading.

Determination of Fiber Orientation Along the Length of Complex Composite Structures Subjected to Internal Pressure and Axial Loading

2012 ◽  
Author(s):  
Rifat Hossain ◽  
Pierre Mertiny ◽  
Jason Carey
Keyword(s):  
Internal Pressure ◽  
Composite Structure ◽  
Fiber Orientation ◽  
Composite Structures ◽  
Axial Loading ◽  
Pressure Vessels ◽  
Variable Cross ◽  
Loading Conditions ◽  
Axially Symmetric ◽  
Fiber Angle

Axially symmetric fiber-reinforced polymer composite structures such as pressure vessels and piping are being widely used in different industrial applications where combined loading conditions may be applied. It is imperative to determine a suitable fiber angle, or a distribution of fiber angles, along the longitudinal direction of the structure in order to achieve best performance in terms of mechanical behavior and strength for structures subjected to combined loadings. To this end, a theoretical study was conducted providing the relationship between the fiber orientation and the loading conditions applied to a composite structure. The aim of this study is to determine the fiber angle variation along the length of an axially symmetric composite structure with variable cross-section considering different ratios of axial loading and internal pressure. As an initial step, netting analysis design theory was implemented in the present study.

Non-Destructive Testing of Thermoplastic Carbon Composite Structures

2020 ◽  
Vol 2020 (1) ◽  
pp. 34-52
Author(s):  
Rafał Szymański
Keyword(s):  
Composite Structures ◽  
Ultrasonic Method ◽  
Composite Panel ◽  
Aviation Industry ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Pulse Technique ◽  
Thermoplastic Matrix ◽  
The Subject ◽  
Non Destructive

AbstractThe article is in line with the contemporary interests of companies from the aviation industry. It describes thermoplastic material and inspection techniques used in leading aviation companies. The subject matter of non-destructive testing currently used in aircraft inspections of composite structures is approximated and each of the methods used is briefly described. The characteristics of carbon preimpregnates in thermoplastic matrix are also presented, as well as types of thermoplastic materials and examples of their application in surface ship construction. The advantages, disadvantages and limitations for these materials are listed. The focus was put on the explanation of the ultrasonic method, which is the most commonly used method during the inspection of composite structures at the production and exploitation stage. Describing the ultrasonic method, the focus was put on echo pulse technique and the use of modern Phased Array heads. Incompatibilities most frequently occurring and detected in composite materials with thermosetting and thermoplastic matrix were listed and described. A thermoplastic flat composite panel made of carbon pre-impregnate in a high-temperature matrix (over 300°C), which was the subject of the study, was described. The results of non-destructive testing (ultrasonic method) of thermoplastic panel were presented and conclusions were drawn.

The effect of nanoparticle additive on surface milling in glass fiber reinforced composite structures

2021 ◽  
pp. 096739112110141
Author(s):  
Ferhat Ceritbinmez ◽  
Ahmet Yapici ◽  
Erdoğan Kanca
Keyword(s):  
Composite Materials ◽  
Glass Fiber ◽  
Composite Structures ◽  
Fiber Composite ◽  
Cutting Speed ◽  
Fiber Reinforced ◽  
Fiber Reinforced Composite ◽  
Reinforced Composite ◽  
Glass Fiber Reinforced ◽  
Composite Layers

In this study, the effect of adding nanosize additive to glass fiber reinforced composite plates on mechanical properties and surface milling was investigated. In the light of the investigations, with the addition of MWCNTs additive in the composite production, the strength of the material has been changed and the more durable composite materials have been obtained. Slots were opened with different cutting speed and feed rate parameters to the composite layers. Surface roughness of the composite layers and slot size were examined and also abrasions of cutting tools used in cutting process were determined. It was observed that the addition of nanoparticles to the laminated glass fiber composite materials played an effective role in the strength of the material and caused cutting tool wear.

Vibration-based delamination evaluation in GFRP composite beams using ANN

2021 ◽  
pp. 096739112110033
Author(s):  
TG Sreekanth ◽  
M Senthilkumar ◽  
S Manikanta Reddy
Keyword(s):  
Finite Element ◽  
Natural Frequency ◽  
Composite Structures ◽  
Composite Beams ◽  
Vibration Characteristics ◽  
Mode Shapes ◽  
Aviation Industry ◽  
Frequency Data ◽  
Fiber Reinforced ◽  
Back Propagation Algorithm

Delamination is definitely an important topic in the area of composite structures as it progressively worsens the mechanical performance of fiber-reinforced polymer composite structures in its service period. The detection and severity analysis of delaminations in engineering areas like the aviation industry is vital for safety and economic considerations. The existence of delaminations varies the vibration characteristics such as natural frequencies, mode shapes, etc. of composites and hence this indication can be effectively used for locating and quantifying the delaminations. The changes in vibration characteristics are considered as inputs for the inverse problem to determine the location and size of delaminations. In this paper Artificial Neural Network (ANN) is used for delamination evaluationof glass fiber-reinforced composite beams using natural frequency as typical vibration parameter. The Finite Element Analysis is used for generating the required dataset for ANN. The frequency-based delamination prediction technique is validated by finite element models and experimental modal analysis. The results indicate that the ANN-based back propagation algorithm can predict the location and size of delaminations in composites with good accuracy for numerical natural frequency data but the accuracy is comparitivelyless for experimental natural frequency data.

Strength Loss in Composite Cylinders Under Impact

1988 ◽  
Vol 110 (2) ◽  
pp. 180-184 ◽  
Author(s):  
A. P. Christoforou ◽  
S. R. Swanson
Keyword(s):  
Composite Structures ◽  
Composite Plates ◽  
Strength Loss ◽  
Pressure Vessels ◽  
Fourier Series Expansion ◽  
Lateral Impact ◽  
Low Velocity ◽  
Expansion Procedure ◽  
The Impact ◽  
Composite Cylinders

The problem of strength loss in composite structures due to impact appears to be important due to the sensitivity of advanced composites to these loadings. Although a number of studies have been carried out on impact of flat composite plates, relatively little work has been done on tubular geometries such as pressure vessels despite the usage in applications. We have addressed the problem of calculating strength loss due to low velocity, lateral impact of composite cylinders. In our model we use an existing Fourier Series expansion procedure to calculate ply stresses and strains, compare these values with allowables to predict fiber breakage during the impact, and finally use fracture mechanics to predict the strength loss due to the impact. Although the model is quite simplified, the general trends of experiments appear to be represented.

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