Framework for a Combined Netting Analysis and Tsai-Wu-Based Design Approach for Braided and Filament-Wound Composites

2013 ◽  
Vol 135 (3) ◽  
Author(s):  
Rifat Hossain ◽  
Jason P. Carey ◽  
Pierre Mertiny
Keyword(s):  
Composite Structures ◽  
Longitudinal Direction ◽  
Industrial Applications ◽  
Pressure Vessels ◽  
Design Tool ◽  
Combined Loading ◽  
Axially Symmetric ◽  
Reinforced Polymer ◽  
Failure Theory ◽  
Filament Wound

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, an approach combining netting analysis and Tsai-Wu failure theory was employed as a design tool to assess critical fiber angles at which applied loadings would cause a structure to fail. Together, the proposed netting analysis and failure theory-based approach constitute a simple, expedient, and convenient design process for complex-shaped structures.

Towards the Development of Filament Wound Composite Structures Submitted to Very High Internal Pressure, Based on Complex Geometry Shapes

2013 ◽  
Author(s):  
Erik Vargas Rojas ◽  
David Chapelle ◽  
Dominique Perreux
Keyword(s):  
Internal Pressure ◽  
Composite Structures ◽  
Complex Geometry ◽  
Industrial Applications ◽  
Filament Winding ◽  
Complex Geometries ◽  
Filament Wound ◽  
Complex Shapes ◽  
Filament Wound Composite ◽  
High Internal Pressure

Industrial applications, especially composite structures bearing high internal pressure, and fabricated using the filament winding process face certain difficulties like the reinforcement of complex shapes, as well as the correct placement of fibers over the surface of a mandrel. In some cases the definition of the manufacturing parameters respond more to cost or time criteria rather than engineering standards, reducing largely the advantages of the said manufacturing process. In order to overcome these obstacles, this research aims to propose a solution that permits to fabricate complex shapes with the desired winding angles at a certain region of complex-shaped mandrels. A numerical tool that simulates the placement of fiber tows over the surface of complex geometries is developed and validated by means of the fabrication of convex and concave composite structures using detachable mandrels. Previous results show that it is feasible to wind complex geometries with good accuracy.

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.

Quality Assessment of Weldable Steel Mark P355NH from Decompression Chamber Construction for Diving

2012 ◽  
Vol 217-219 ◽  
pp. 2381-2387
Author(s):  
Doru Romulus Pascu ◽  
Radu Alexandru Roşu ◽  
Iuliana Duma ◽  
Horia Daşcău
Keyword(s):  
Test Temperature ◽  
Transverse Direction ◽  
Mechanical Characteristics ◽  
Longitudinal Direction ◽  
Pressure Vessels ◽  
Fine Grained ◽  
Weldable Steel ◽  
Breaking Energy ◽  
Fine Grained Steels ◽  
Selection Of

Non-alloyed P355NH steel according to EN 10028-3:2003 belongs to a group of fine-grained steels for pressure vessels being used in welded construction at decompression chamber for divers. Values of the chemical, structural and mechanical characteristics and steel toughness experimentally determined fit the analyzed steel in P355NH steel group according to EN 10028-3:2003. The toughness of the analyzed steel at the test temperature of -30°C is characterized by high values of fracture energy KV in longitudinal direction between 48 and 86 J and on transverse direction between 17 and 34J. Steel toughness at the test temperature of -30°C required by ABS standard (in Section 4/5.3 and Table 1) provides for breaking energy KV of min. 35J, with ductile fracture surfaces, value that is not respected at some lots of the three batches (A, B, C) of steel. Finally, based on the direct correlation established between HV10 hardness of the fine structure and the toughness it was made a selection of the lots of non-alloy steel P355NH which correspond to ABS norm for welded construction of the decompression chamber for divers

Performance in Fire of Fibre Reinforced Polymer Strengthened Concrete Beams and Columns: Recent Research and Implications for Design

2014 ◽  
Vol 5 (4) ◽  
pp. 353-366 ◽  
Author(s):  
Mark Green ◽  
Kevin Hollingshead ◽  
Noureddine Bénichou
Keyword(s):  
Conceptual Model ◽  
Concrete Beams ◽  
Design Tool ◽  
Fire Performance ◽  
Reinforced Polymers ◽  
Reinforced Polymer ◽  
Practical Design ◽  
Fibre Reinforced Polymer ◽  
Full Scale Tests ◽  
In Fire

This paper considers the fire performance of concrete beams and columns that have been strengthened with fibre reinforced polymers (FRPs). Results from four recent full-scale tests are presented. A newly developed type of insulation was employed and the thickness of the insulation (15 to 20 mm) was approximately half that provided in earlier tests. All of the members survived four hours of the fire exposure. A conceptual model for design to determine when insulation is required is also presented. Further research needed to fully develop the conceptual model to a more practical design tool is outlined.

Analysis of Material Coating for Damping in Beam Structures

2010 ◽  
Vol 442 ◽  
pp. 202-210
Author(s):  
S.H. Raza ◽  
M.A. Malik ◽  
W. Akram
Keyword(s):  
Turbine Blades ◽  
Beam Theory ◽  
Industrial Applications ◽  
Theory Model ◽  
Design Tool ◽  
Coating Material ◽  
Mode Shapes ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Finite Element Procedure

Vibratory stresses are the main cause of material failure in aerospace/mechanical structures and machine components. Failure also occurs due to these vibratory stresses in gas turbine engines and rotating machinery components while operating at resonant frequency. A magnetomechanical coating material is used as a very effective method for damping of these stresses. Vibratory stress damping in components like turbine blades through magnetomechanical coating material is well known in literature. However, the geometric correlations for the varying coated beam are not well established. We have utilized a cantilever beam as the basic geometry for this investigation to establish a correlation for varying coating. Beam theory is applied as a mathematical model for obtaining the mode shapes for the beam. A finite element procedure is performed to acquire the data and this data is then correlated with beam theory model for initial verification. This data is further evaluated to form the required model for calculating thickness of coating for a beam. The resulting parametric correlation is verified through comparison with the already published experimental data available in literature. This correlation can be used as a design tool for suppression of vibratory stresses in industrial applications.

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.

scholarly journals Sequential Laser–Mechanical Drilling of Thick Carbon Fibre Reinforced Polymer Composites (CFRP) for Industrial Applications

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2136
Author(s):  
Sharizal Ahmad Sobri ◽  
Robert Heinemann ◽  
David Whitehead
Keyword(s):  
Carbon Fibre ◽  
Polymer Composites ◽  
Weight Ratio ◽  
High Strength ◽  
Industrial Applications ◽  
Fibre Laser ◽  
Reinforced Polymer ◽  
Carbon Fibre Reinforced Polymer ◽  
Fibre Reinforced Polymer ◽  
Thrust And Torque

Carbon fibre reinforced polymer composites (CFRPs) can be costly to manufacture, but they are typically used anywhere a high strength-to-weight ratio and a high steadiness (rigidity) are needed in many industrial applications, particularly in aerospace. Drilling composites with a laser tends to be a feasible method since one of the composite phases is often in the form of a polymer, and polymers in general have a very high absorption coefficient for infrared radiation. The feasibility of sequential laser–mechanical drilling for a thick CFRP is discussed in this article. A 1 kW fibre laser was chosen as a pre-drilling instrument (or initial stage), and mechanical drilling was the final step. The sequential drilling method dropped the overall thrust and torque by an average of 61%, which greatly increased the productivity and reduced the mechanical stress on the cutting tool while also increasing the lifespan of the bit. The sequential drilling (i.e., laser 8 mm and mechanical 8 mm) for both drill bits (i.e., 2- and 3-flute uncoated tungsten carbide) and the laser pre-drilling techniques has demonstrated the highest delamination factor (SFDSR) ratios. A new laser–mechanical sequence drilling technique is thus established, assessed, and tested when thick CFRP composites are drilled.

Optimum design of composite structures with ply drop-offs using response surface methodology

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Camila Aparecida Diniz ◽  
Yohan Méndez ◽  
Fabrício Alves de Almeida ◽  
Sebastião Simões da Cunha Jr ◽  
G.F. Gomes
Keyword(s):  
Response Surface Methodology ◽  
Natural Frequency ◽  
Design Variable ◽  
Composite Structures ◽  
Laminate Plate ◽  
Longitudinal Direction ◽  
Stacking Sequence ◽  
Direct Influence ◽  
Optimization Strategy ◽  
Content Type

Purpose Many studies only take into account the ply stacking sequence as the design variable to determine the optimal ply drop-off location; however, it is necessary to optimize other parameters that have a direct influence on the ply drop-off site such as which plies should be dropped and in which longitudinal direction. That way, the purpose of this study is to find the most significant design variables relative to the drop-off location considering the transversal and longitudinal positions, seeking to achieve the optimal combination of ply drop-off locations that provides excellent performance for the laminate plate. Design/methodology/approach This study aims to determine the optimal drop-off location in a laminate plate using the finite element method and an approach statistical with design of experiments (DOE). Findings The optimization strategy using DOE revealed to be satisfactory for analyzing laminate structures with ply drop-offs, demonstrating that not all design factors influence the response variability. The failure criterion response variable revealed a poor fit, with an adjusted coefficient of determination lower than 60%, thus demonstrating that the response did not vary with the ply drop-off location. Already the strain and natural frequency response variables presented high significance. Finally, the optimization strategy revealed that the optimal drop-off location that minimizes the strain and maximizes the natural frequency is the ply drop-off located of the end plate. Originality/value It was also noted that many researchers prefer evolutionary algorithms for optimizing composite structures with ply drop-offs, being scarce to the literature studies involving optimization strategies using response surface methodology. In addition, many studies only take into account the ply stacking sequence as the design variable to determine the optimal ply drop-off location; however, in this study, the authors investigated other important parameters that have direct influence on the ply drop-off site such as which plies should be dropped and in which longitudinal direction.

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