GLARE Materials Research Articles

Development of Forming Limit Curve for Glare in a semi-cured state using Hydro-bulging test method

Forming limit curve (FLC) is a valuable tool for predicting the formability of materials. Considering the need to develop FLC for fiber metal laminates (FMLs), Glare in a 2/1 sequence was prepared for the development of FLC. The prepreg used was glass fiber stacked in between the aluminum sheets in a semi-cured state, which allows for enhanced strain percentage and helps predict the maximum forming limit of Glare. The experimental data was accumulated by comprehensively testing parameters like pressure rate, temperature, and blank holding pressure. The results show that at higher temperatures and reduced pressure rate and blank holding pressure, the formability of Glare can be enhanced. This study helps predict the safe zone when forming Glare and manufacturing small intricate parts of Glare material in engineering applications.

Optimizing the Process Parameters of Hydro-Deep Drawing of Cylindrical Parts Using Fiber Metal Laminates

Forming Fiber Metal Laminates (FMLs) is still challenging. There are some inherent limitations to forming smaller and complex-shaped FML parts. In particular, the process parameters have a major impact on the final FMLs part. In this paper, several investigations were conducted to optimize these process variables. In the investigations, different Blank Holder Gap (BHG) thicknesses were used to predict the optimal range; variable Blank Holder Force (BHF) and Cavity Pressure (CP) were chosen to make the results more convincing. Based on the numerical analysis, it is found that the optimum BHF should be between 10 to 15 KN; CP has a range from 8 to 10 MPa; optimum BHG should be 1.0 mm. And through using these predicted process parameters, a successful Glare cup has been formed. Furthermore, the forming performance of the Glare material is improved and the laminate has shown better formability. Finally, optimized process variables can be used for mass production of FMLs parts.

A REVIEW OF NEW COMPOSITE MATERIALS FOR THERMAL PROTECTION IN AN AERO-ENGINE APPLICATION

The paper is aimed at exploring new composite materials for thermal protection in an aero-engine application. Aluminium hybrid composites have been widely used to substitute materials in the aerospace industry because of their high thermal resistance, wear resistance and strength-to-weight ratio. This review article covers standard fire test results of different types of burners and burn-through times of the composites and polymeric materials. The paper evaluates the performance of different structural composite materials including synthetic fibres, natural fibres and some type of coating on the materials in a pool-fire scenario. It also deals with the practical use of flame retardancy and performance factors including safety in an aircraft related to polymer composites. It was found that most of the materials used could only be categorized as fire resistance materials except GLARE materials and synthetic/natural fibre composites and aerogel composites which showed the characteristic of fireproof materials.

КОНЦЕПТУАЛЬНОЕ ПРОЕКТИРОВАНИЕ КОНСТРУКЦИИ КРЫЛА ИЛИ ФЮЗЕЛЯЖА МАГИСТРАЛЬНОГО САМОЛЕТА ИЗ МЕТАЛЛОПОЛИМЕРНЫХ КОМПОЗИЦИОННЫХ МАТЕРИАЛОВ

The analysis of existing aircraft structures made of metal-polymer composite materials is carried out, and a list of them with passport characteristics is compiled. The Fokker F-27 Friendship, Boeing-777 and Airbus A380, which use ARALL and GLARE materials, were selected as the aircraft under study. Formulas are determined and the distribution of normal force flows between metal and composite elements in the composition of MPCM based on aluminum sheets (aluminum-fiberglass – SIAL- 1-1, SIAL-3-1 and SIAL-1441 (9/8)) and titanium alloys (samples of titanium-carbon fiber from the patent-Example 1 and Example 3). To determine these parameters, the formulas used for a composite structure made of different materials are used. On the basis of the specification known MPCM the modified formula mixture rule for calculating the strength of new materials with a given set of orientation angles of PCM and the presence of layers of sheet metal, a comparison with standard mechanical characteristics and to show the efficiency of these formulas. Using these formulas, you can determine the strength characteristics for an arbitrary composition of the MPCM package. The features of the choice of design permissible stresses for the design of the airframe of a mainline aircraft made of metal-polymer composite material are highlighted. The concept of designing aircraft airframe elements using MPCM is considered. The results of this work will allow us to determine the rational components of the metal-polymer composite material and the structure of their distribution in the airframe design at the preliminary design stage.

Experimental and numerical investigation of fiber metal laminate forming behavior using a variable blank holder force

Structural integrity, fuel efficiency, and reduced emission of greenhouse gases are the topmost priorities of the modern-day aerospace and automobile industries. Fiber-metal laminates (FMLs) can reduce most of these concerns by reducing a significant amount of weight without compromising structural reliability. Although this material was invented a few decades ago, large scale production, especially the forming process of small and complex-shaped products, has not matured yet. The necessity of manual processing makes it more cost-intensive and time-consuming. The forming difficulty comes with the limited elongation of the fiber layers compared to the metallic layers. As a result, the conventional approaches to form FMLs parts are not very suitable. In this paper, an investigation has been conducted to improve the drawability of FMLs sheets in deep drawing of cylindrical cups, made of semi-cured Glare material. A variable blank holder force (VBHF) method was proposed, which means the variation of the friction force of the holder and the laminate on contact surfaces, as a function of the position of outer flange edge. Fracture and wrinkling limits have been determined, and a BHF control trajectory has been presented to improve the forming quality, increase the drawing depth, and eliminate defects. Both experimental and numerical results from the VBHF were compared with constant BHF results. It is evident that the proposed VBHF scheme helps to improve the drawing quality compared to the conventional constant BHF. As a result, this method can enhance the production rate as well.

Process Control Improvement in Deep Drawing of Hemispherical Cups Made of GLARE Material

Controlling the material flow under the blank holder in hydroforming is a delicate point that can be controlled by the blank holder force (BHF), cavity pressure (CP) and the blank holder gap (BHG). BHG is one of the effective parameters to control the material flow. A numerical and experimental approach studied the impact of the BHG on the Hydromechanical Deep Drawing (HDD) of a hemispherical cup made with 2/1 Glare sheets, including another two factors, CP and BHF. BHGs with different thickness was used in the experiments to form Glare Laminate. Simulation and experiment illustrate that an optimized value of these parameters has a good effect on the forming quality and depth of the final product. Finally, an appropriate value of the BHG is projected and the explanations of the failure modes are discussed.

An Investigation into Process Parameters Effect on the Formability of GLARE Materials Using Stamp Forming

The use of laminates allows an optimization of the material properties, these hybrid materials can unravel some problems in the industrial sector, particularly in aerospace, and advanced automotive industry. Fiber Metal Laminates (FMLs) can be produced both by laminating and by forming. Flat laminates are easier to produce by the lay-up process, for small and relatively complex shapes with low thickness there are significant challenges in the forming process even for small drawing ratios, In this investigation, a cylindrical GLARE cup was chosen, this shape with sharp curves and vertical geometrical walls, still face numerous difficulties in the forming procedure. Numerical simulations have been used and compared with the experimental results in the stamp forming to achieve good forming quality with higher depth. An extensive investigation of the effect of process variables has been done such as blank-holding force, and blank holder gap and the curing condition. Also, their roles in wrinkles formation, tearing and thinning, as well as formability have been performed. The results show a good agreement between the experiments and the numerical simulation and show clearly that the application of blank holder force and blank holder gap within specified limits has a positive effect on the quality of the formed cup and leads to higher depths. Understanding these parameters and the GLARE forming conduct and having a decent choice of these parameters can give the advantage to achieve smaller and more complex shapes with higher depth, especially for large scale manufacturing. Finally, this investigation can expand the modern application regions of the FMLs and GLARE parts.

An Investigation into the Formability and Processes of GLARE Materials Using Hydro-bulging Test

Our research mainly focuses on investigating the formability and processes of GLARE materials in the hydro-bulging test. Finite element simulation software ABAQUS/Explicit is applied to study the state of stress and strain as well as wall thickness distribution while experiments have done to validate the simulation results. The results indicate that cavity pressure and blank holder force have a significant effect on the forming behavior compared with traditional metal blanks. Curing process is also introduced in the production stage after first forming step. This study will increase the application of composite laminate manufacturing and open new ways for specialists working on high-strength lightweight material for future research.

Experimental Investigation of Static & Dynamic loading conditions for CLARE Composite Material

In Aerospace and Automobile sector weight plays significant role. The reason behind this is efficient & effective working of aircraft and motor vehicles. It also needs the high strength to weight ratio. This requirement is fulfilled by the composite materials.In this research, CLARE is a hybrid composite consisting of thin aluminium, carbon fiber & epoxy layer is found to be alternate for GLARE materials consisting of thin aluminium, glass fiber, & epoxy layer, have been using over 36 years for wide range of advance aerospace structural applications but having comparatively more weight than CLARE. CLARE laminates offer a distinctive amalgamation of properties such as outstanding fatigue resistance, high specific static properties, exceptional impact resistance, high strength to weight ratio, corrosion resistance, Stiffness and ease of manufacture and repair. But the delaminating occurs in the sheets of aluminum in GLARE material is eliminate by CLARE materialSolicitation of CLARE materials for the skin or the outer parts here presented the need of CLARE materials in supportive structural members; the present work focuses on the fabrication various structural cross sections of Clare material. For fabrication purpose selected method is hand lay-up. Static & dynamic analysis of these Clare material cross sections was carried out; it follows a comparative study with the aluminium cross sections gives that the Clare has a better performance.

Experimental Investigation of Static & Dynamic Loading Conditions for Glare Material

Now a day’s weight plays a very important role in aircraft industries. The reason behind this is efficient & effective working of aircraft. It also needs the high strength to weight ratio. This requirement is fulfilled by the composites. In this research, GLARE is a hybrid composite consisting of thin aluminum, glass fiber & epoxy layer. GLARE materials have been using over 36 years for wide range of advance aerospace structural applications. GLARE laminates offer a distinctive amalgamation of properties such as outstanding fatigue resistance, high specific static properties, exceptional impact resistance, good flame resistance, corrosion resistance and ease of manufacture and repair. But the delaminating occurs in the sheets of aluminum and similarly aluminum wire mesh is used. Solicitation of GLARE materials for the skin or the outer parts here presented the need of GLARE materials in supportive structural members; the present work focuses on the fabrication various structural cross sections of glare material. For fabrication purpose, selected method is hand lay-up. Static & dynamic analysis of these glare material cross sections was carried out; it follows a comparative study with the aluminum cross sections gives that the glare has a better performance.

Low velocity impact response of basalt-aluminium fibre metal laminates

This work reports on a preliminary study to assess the response of fibre metal laminates (FMLs) made of stacked layers of basalt fabric epoxy prepreg and aluminium sheets to low velocity impact and, through comparison with published results for Glare materials, benchmark their impact performance. Comparison is also made with results from plates of monolithic aluminium with comparable thickness. The effect of impactor size is also investigated whilst the impact energies were selected with the aim of inducing first crack (FC) and through the thickness crack (TTT) on the FML samples. Optical microscopy and profilometry were used to elucidate fracture mechanisms and the dent depth. The response of basalt fibre metal laminates was found to be both significantly influenced by the impactor size and fairly positive, proving to be competitive with monolithic aluminium plates although some issues about the aluminium/basalt interface have been raised.

Fatigue behaviour of riveted Glare lap joints

Fibre metal laminates, such as Glare, are a family of materials with very interesting properties for fatigue‐critical applications. This article describes the results of a research programme carried out to evaluate the fatigue and damage tolerance characteristics of riveted Glare lap joints, representative of fuselage longitudinal joints. The comparison with the behaviour of metallic joints shows that different contributions are made to the total fatigue life, with the crack propagation life being by far the longer one for the Glare material whereas the crack nucleation life covers almost the entire fatigue life for metallic joints. Design rules should take this peculiar behaviour into consideration, to achieve the maximum benefit in the use of this class of materials in fatigue‐critical applications.

Shielding against space debris. A comparison between different shields: The effect of materials on their performances

The space environment requires the Space Station to be shielded against orbital debris. A technological programme undertaken by the European Space Agency has led to a preliminary definition of the shield configuration for the European Attached Pressurized Module. The envisaged shield is a modified Whipple shield. A second bumper is located midway between the first bumper and the backwall. The work described has been initiated to quantify experimentally the merits of different shields compatible with the APM system requirements. For this technological investigation, two requirements had to be satisfied. The spacing between the front bumper and the backwall had to be limited to 120 mm. The backwall thickness could not be reduced to technological limits as it has structural functions as well. In addition, the long life requirements of the Space Station precludes the use of unproved materials for the external parts of the shield. Different materials have been tried as second bumper. The effect of the first bumper thickness on the projectile fragmentation has been explored as well. Shields based on Aluminium, Kevlar and Glare have been investigated. Kevlar 29 fabrics impregnated with epoxy resin were used for this work. Glare is a material developed to improve the fatigue strength of metal structures. It is primarily intended for aircraft skin applications. Glare consists of a 60 percent fibre volume adhesive prepreg with high-strength unidirectional or cross-ply R-glass fibres. A variety of lay-up sequences is available ranging from 2 1 (two layers of aluminium alloy sheet bonded by one layer of prepeg) to any number of layers. The 2 1 layers version of the Glare material has been used for this work. The tests results indicate the performances of materials can change significantly with the impact conditions. Glare shows the best performances in the low velocity regime while Kevlar is very promising in the high velocity regime. It is concluded the use of Kevlar can improve substantially the performances of the APM shield.

Crack growth and residual strength characteristics of two grades of glass-reinforced aluminium ‘Glare’

Crack growth and residual strength tests have been conducted on both Glare 3 and Glare 4 material. Results have been compared with those for 2024-T3 monolithic aluminium alloy showing improvements in fatigue life of up to 100 times and improvements in residual strengths of up to 40%. The potential weight savings and general structural performance improvements of the Glare material make it most attractive for future aerospace vehicle design, despite its current higher manufacturing costs.