Manufacturing cost/design guide /MC/DG/ for metallic and composite structures

1981 ◽  
Author(s):  
B. NOTON ◽  
R. PRESTON
Keyword(s):  
Composite Structures ◽  
Manufacturing Cost ◽  
Design Guide

Resin Infusion of Triaxially Braided Preforms With Through-the-Thickness Reinforcement

2001 ◽  
Author(s):  
Jay R. Sayre ◽  
Alfred C. Loos
Keyword(s):  
Composite Structures ◽  
High Performance ◽  
Volume Fraction ◽  
Three Dimensional ◽  
Element Model ◽  
Manufacturing Cost ◽  
Fiber Volume ◽  
Resin Infusion ◽  
Infiltration Process ◽  
High Fiber

Abstract Vacuum assisted resin transfer molding (VARTM) has shown potential to significantly reduce the manufacturing cost of high-performance aerospace composite structures. In this investigation, high fiber volume fraction, triaxially braided preforms with through-the-thickness stitching were successfully resin infiltrated by the VARTM process. The preforms, resin infiltrated with three different resin systems, produced cured composites that were fully wet-out and void free. A three-dimensional finite element model was used to simulation resin infusion into the preforms. The predicted flow patterns agreed well with the flow pattern observed during the infiltration process. The total infiltration times calculated using the model compared well with the measured times.

Performance Evaluation of Notched Biaxial Braided Composites

2004 ◽  
Author(s):  
Jitendra S. Tate ◽  
Ajit D. Kelkar ◽  
Ronnie Bolick
Keyword(s):  
Composite Structures ◽  
Low Cost ◽  
Impact Resistance ◽  
High Volume ◽  
Manufacturing Cost ◽  
Braided Composites ◽  
Static Tensile Loading ◽  
New Process ◽  
Static Tensile ◽  
Potential Benefits

Braided composites have good properties in mutually orthogonal directions, more balanced properties than traditional tape laminates, and have potentially better fatigue and impact resistance due to the interlacing. Another benefit is reduced manufacturing cost by reducing part count. Because of these potential benefits braided composites are being considered for various applications ranging from primary/secondary structures for aerospace structures [1]. These material systems are gaining popularity, in particular for the small business jets, where FAA requires take off weights of 12,500 lb. or less. The new process, Vacuum Assisted Resin Transfer Molding (VARTM), is low cost, affordable and suitable for high volume manufacturing environment. Recently the aircraft industry has been successful in manufacturing wing flaps, using carbon fiber braids and epoxy resin and the VARTM process. To utilize these VARTM manufactured braided materials to the fullest advantage (and hence to avoid underutilization), it is necessary to understand their behavior under different loading and environmental conditions. This will reduce uncertainty and hence reduce the factor of safety in the design. It is well known fact that the strength of the composite structure reduces because of discontinuities and abrupt change in the cross-section. Accurate knowledge of strength and failure mechanism of notched and unnotched composites is very important for design of composite structures. This research addresses the behavior of notched braided composites under static tensile loading.

Complex three- dimensional-shaped knitting preforms for composite application

2016 ◽  
Vol 46 (7) ◽  
pp. 1536-1551 ◽  
Author(s):  
T Hamouda
Keyword(s):  
Composite Structures ◽  
Three Dimensional ◽  
Woven Fabrics ◽  
Polymer Materials ◽  
Fiber Reinforced Polymer ◽  
Manufacturing Cost ◽  
Two Dimensional ◽  
Fiber Reinforced ◽  
Reinforced Polymer ◽  
Complex Shapes

For decades, street lighting and electric poles are made of metal and it is vulnerable to corrosion due to the harsh weather and chemicals. To overcome such essential problems, galvanized iron is used although it adds more hard work to increase the manufacturing cost. Therefore, fiber reinforced polymer lighting pole is proposed. Fiber reinforced polymer materials possess many advantages such as corrosion resistance, high specific strength and stiffness, etc. Two-dimensional woven fabrics and three-dimensional woven fabrics preforms are used to produce composite structures. However, complex shapes cannot be manufactured as a one piece preform. Woven fabrics, whether two-dimensional or three-dimensional need to be cut into patterns to finally produce the complex shapes. These processes add more cost and time to the final composite products. In this research, innovative technique to produce a three-dimensional complex shape knitted preform using regular flat-knitting machine will be presented. Production of such shaped three-dimensional preform permits the production of one piece-shaped preform without any connection or further sewing processes. Produced knitted preform can be used for various reinforcement applications such as light and communication poles, scaffold façades, traffic sign, oars, and wind mill blades.

A review on modeling of the thermal conductivity of polymeric nanocomposites

e-Polymers ◽  
2012 ◽  
Vol 12 (1) ◽  
Author(s):  
Sh. Jafari Jafari Nejad
Keyword(s):  
Thermal Conductivity ◽  
Composite Structures ◽  
Heterogeneous Media ◽  
Conductivity Measurement ◽  
Theoretical Models ◽  
Particle Packing ◽  
Manufacturing Cost ◽  
Polymeric Nanocomposites ◽  
The Matrix ◽  
Thermally Conductive

AbstractThis review reports recent advances in the field of thermal conductivity of polymeric nanocomposites. Thermally conductive polymeric nanocomposites can be used for replacing metal parts in several applications, such as liquid cooling and ventilation garment, power electronics, electric motors and generators, heat exchangers, etc., because the polymers have some privileges such as light weight, corrosion resistance, lower manufacturing cost and ease of processing. In this study, the thermal conductivity measurement and modeling of polymeric nanocomposites are discussed in general, and detailed examples are also drawn from the scientific literature. Many theoretical models are available to predict the thermal conductivity of nanocomposites. The simplest of these are mixture rules such as series, parallel, and geometric models. However, the series model typically over predicts the thermal conductivity, whereas the parallel model tends to under predict the thermal conductivity of the nanocomposites. Other models such as the Hamilton-Crosser model and the Lewis-Nielsen model are based on particle size, geometry, and the manner of particle packing in the matrix. Also, there are various effective medium approaches (EMA) like the Maxwell-Garnett (MG) approximation to analyze the thermal transport behaviour in heterogeneous media such as thermal conductivity of some composite structures.

Practical design of tapered composite structures using the manufacturing cost concept

2001 ◽  
Vol 51 (3) ◽  
pp. 285-299 ◽  
Author(s):  
Jung-Seok Kim ◽  
Chun-Gon Kim ◽  
Chang-Sun Hong
Keyword(s):  
Composite Structures ◽  
Manufacturing Cost ◽  
Practical Design

scholarly journals Irreversible and Repeatable Shape Transformation of Additively Manufactured Annular Composite Structures

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1383
Author(s):  
Bona Goo ◽  
Jong-Bong Kim ◽  
Dong-Gyu Ahn ◽  
Keun Park
Keyword(s):  
Composite Structures ◽  
Memory Function ◽  
Dimensional Accuracy ◽  
Transformation Method ◽  
Manufacturing Cost ◽  
Thermal Stimulus ◽  
4D Printing ◽  
Shape Transformation ◽  
Shape Transformations ◽  
Accuracy And Repeatability

Four-dimensional (4D) printing is a unique application of additive manufacturing (AM) which enables additional shape transformations over time. Although 4D printing is an interesting and attractive phenomenon, it still faces several challenges before it can be used for practical applications: (i) the manufacturing cost should be competitive, and (ii) the shape transformations must have high dimensional accuracy and repeatability. In this study, an irreversible and repeatable thermoresponsive shape transformation method was developed using a material extrusion type AM process and a plain thermoplastic polymer (ABS) without a shape-memory function. Various types of annular discs were additively manufactured using printing paths programmed along a circular direction, and additional heat treatment was conducted as a thermal stimulus. The programmed circumferential anisotropy led to a unique 2D-to-3D shape transformation in response to the thermal stimulus. To obtain more predictable and repeatable shape transformation, the thermal stimulus was applied while using a geometric constraint. The relevant dimensional accuracy and repeatability of the constrained and unconstrained thermal deformations were compared. The proposed shape transformation method was further applied to AM and to the in situ assembly of a composite frame–membrane structure, where a functional membrane was integrated into a curved 3D frame without any additional assembly procedure.

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