Composite Tapes Research Articles

A Digital Shadow for the Infrared-based Tape Laying Process of Tailored Blanks out of Thermoplastic Unidirectional Tape

Due to its benefits in creating load and waste optimized composites, the manufacturing of tailored composites blanks has gained increased attention in industry. The Fraunhofer IPT has developed an infrared (IR)-based, in-situ tape laying process of thermoplastic, unidirectional composite tape proving to be a material and cost efficient technology for producing tailored composite blanks. An important part in the in-situ process is finding optimal process parameters regarding high productivity and quality. Besides the optimization of process parameters, machine design as well as blank design including geometry and ply book involve process induced effects. Different fibre angles, amount of layers or insufficient radiation power can result in various defects of the blank, such as residual stresses or non-sufficient consolidation between layers. This study investigates how Digital Shadows (DS) help to characterize the IR-based tape laying process of different blank designs. DS for the tape laying process are created showing relevant parameters localised to its position within the laminate. A temperature sensor is integrated in order to attain data for process characterization. A straightforward design of experiments is conducted demonstrating temperature profiles as well as temperature dependencies between the amount of layers and the size of the laminate.

Blocking force measurement of shape memory polymer composite hinges for space deployable structures

This study introduces a method for measuring the blocking force of a shape memory polymer composite hinge to quantify the performance of a shape memory polymer composite hinge for space deployable structure applications. A detailed design of how to select heating elements for a self-deployable configuration is also suggested. The shape memory polymer composite hinge consists of two reverse carpenter shape memory polymer composite tapes that were made from carbon-epoxy fabric, shape memory polymer resin, and two heating elements. The heating elements were attached to the shape memory polymer composite tape using the composite manufacturing method, and they were used as the heating source in the deployment test. The blocking force and moment of the hinge were measured using a pulley–mass system setup to examine the mechanical performance of the hinge. During the test, the shape change was recorded with a camera to calculate the moment arms. While the blocking force was 7.21 N in the initial test, it decreased slightly with the working cycle and was 6.27 N in the repeated test. The maximum hinge moment was 0.47 N m in the repeated test. In addition, the results revealed that a pop-up phenomenon occurred at the middle period of deployment. These results confirm that the shape memory polymer composite hinge works well with heating elements and provide a guideline for performance evaluation of the shape memory polymer composite hinge.

Stowage and Deployment of a Viscoelastic Orthotropic Carbon-Fiber Composite Tape Spring

Strain energy deployable composite structures offer spacecraft designs reduced payload and compact volume. One of the greatest advantages presented by deployable composite structures arises from their ability to maintain high-strain configurations for extended periods of stowage. Because of the viscoelastic nature of the polymer matrix, the stowed composite structure undergoes stress relaxation that results in a decrease of the energy available for deployment. This paper focuses on a three-layered carbon-fiber-reinforced polymer composite deployable structure, known as a tape spring. Stress relaxation testing was used to define the viscoelastic behavior of the epoxy matrix. Experimental long-term stowage and deployment testing was performed on the tape spring specimens. Finite element simulations considering viscoelastic, orthotropic stress relaxation were developed to predict the effects of stress relaxation on the deployment of a tape spring.

Manufacture of steel–CF/PA6 hybrids in a laser tape placement process: Effect of first-ply placement rate on thermal history and lap shear strength

This paper investigates the manufacture of selectively reinforced metal/composite hybrids in a laser-assisted automated tape placement process. Carbon-fibre/PA6 composite tapes were applied to PA6-coated steel substrates. The bonding of the first-ply to the substrate is critical to the success of the hybrid; the effect of first-ply placement rate was investigated for speeds of 25 mm/s, 50 mm/s, 100 mm/s. The interfacial bond strength of the hybrid laminates was determined by ASTM D3165 lap shear tests. A 3D finite element thermal model was formulated to elucidate the thermal behaviour for increasing first-ply placement rate. A method for increasing model efficiency was shown to significantly decrease the computational difficulty while maintaining solution accuracy. Raising the first-ply placement rate from 25 mm/s to 100 mm/s resulted in a fourfold increase in lap shear strength with a maximum value of 22 MPa. The greater strength at higher speeds is attributed to improved synchronisation of the temperature and consolidation pressure history.

Lay-Up and Consolidation of a Composite Pipe by In Situ Ultrasonic Welding of a Thermoplastic Matrix Composite Tape.

In this work, the potential of preformed thermoplastic matrix composite tapes for the manufacturing of composite pipes by filament winding assisted by in situ ultrasonic welding was evaluated. Unidirectional tapes of E-glass-reinforcedamorphous poly (ethylene terephthalate) were laid up and consolidated in a filament winding machine that was modified with a set-up enabling ultrasonic welding. The obtained composite specimens were characterized by means of morphological and dynamic mechanical analysis as well as void content evaluation, in order to correlate welding parameters to composite properties.

Excellent mechanical properties of long multiwalled carbon nanotube bridged Kevlar fabric

The major causes of failure of Kevlar reinforced composites are inter-yarn slippage and poor adhesion with polymer. Herein, long length multiwalled carbon nanotubes (MWCNTs) are used as a secondary reinforcement to enhance the interfacial interaction between Kevlar and epoxy through bridging action. Different wt. % of MWCNT based Kevlar reinforced hybrid composite tape and their laminar composites have been prepared and their quasi-static unidirectional and dynamic mechanical properties are studied. It is found that the maximum tensile strength, Young's modulus and storage modulus of optimized i.e. 0.3 wt % of MWCNTs in epoxy resin (0.3KE) composite showed an overall improvement of ∼81%, ∼56% and ∼139%, respectively over base line composite tape (KE). The flexural modulus, Young's modulus and storage modulus of 0.3 wt % multi-scaled laminar composite (KEC) showed an overall improvement of ∼33%, ∼50%, and ∼233%, respectively over KE. The effects of MWCNTs on interfacial properties of multi-scaled composite tapes are correlated by Raman spectral shift, FTIR and XRD analysis. Further the bridging actions of long length MWCNTs are visualized by using high resolution transmission electron microscopy.

Analysis of torsional deformation-induced degeneration of critical current of Bi-2223 HTS composite tapes

A deformation-induced degradation model based on Weibull distribution function of statistical damage of superconducting filaments is developed to explore the influence of the torsional displacement on the critical current of Bi-2223 high temperature superconducting (HTS) composite tapes. It is extended in view of the critical current degradation mechanism of HTS tapes under uniaxial deformation. A longitudinal strain is introduced to unify the relation between uniaxial and torsional strain for the tapes. The extended model shows good predictions on the critical current degradation of the HTS tapes with torsional deformation in comparison with experiment data. The quantitative analysis indicates that the tensile longitudinal strain arised from torsional deformation plays a dominant role for superconducting filaments damage evolution compared to the compressive one, in which the irreversible degradation is always induced to remarkably reduce the critical current. Furthermore, a structural optimization design to enhance the carrying-current ability is achieved where the superconducting core should be less located at the tensile region of the HTS composite tapes.

Aerospace growth leads to composites alliances

Hexcel and Arkema will collaborate in the development of composite tapes, while Toray Industries has agreed to buy a Dutch manufacturer of carbon fiber preimpregnated with adhesive, known as prepreg. Both moves are aimed at increasing the chemical firms’ positioning in the aircraft materials market. At an R&D facility planned for France, the Hexcel-Arkema alliance will harness Hexcel’s composites expertise to develop carbon-fiber-based tapes that incorporate Arkema’s polyetherketoneketone polymers. Meanwhile, Toray is paying $1.15 billion for TenCate Advanced Composites, a company that specializes in carbon fiber prepreg for the production of small and medium aircraft. Toray, the world’s largest carbon fiber producer, already supplies the material to the large aircraft makers Boeing and Airbus. The TenCate acquisition will expand Toray’s client base and product development capabilities, the Japanese firm says.

EVALUATION OF DETERMINATION OF CONSTRAINTS AND THE REASONING OF THE METHOD OF SETTLEMENT AND SUBMISSION OF THE COMPOSITE TAPE ON CONCRETE

The article presents the results of experimental studies of the strength of composite tape fastening on concrete under static and cyclic stretching loads.

Cryogenic performance of single polymer polypropylene composites

The main objective of the experimental study detailed in this paper is to investigate the performance of fully recyclable, lightweight, low-cost, thermoplastic Polypropylene (PP) composite tapes at low temperatures. Coupons made of [±45] and [0/90] laminates are subjected to tensile and 3-point bending tests at room temperature as well as at −196 °C. In addition to that, cryogenic low velocity impact tests at 268 J and 777 J impact energies are performed on tubular structures. The results are indicating that the laminates made of PP tapes have sufficient ductility for cryogenic applications. Low velocity impact tests showed that the viscoelastic behavior of the material is preserved, even at such low temperatures and more than 72% of impact energy is absorbed by the material.

Multi-Response Parameter Interval Sensitivity and Optimization for the Composite Tape Winding Process.

The composite tape winding process, which utilizes a tape winding machine and prepreg tapes, provides a promising way to improve the quality of composite products. Nevertheless, the process parameters of composite tape winding have crucial effects on the tensile strength and void content, which are closely related to the performances of the winding products. In this article, two different object values of winding products, including mechanical performance (tensile strength) and a physical property (void content), were respectively calculated. Thereafter, the paper presents an integrated methodology by combining multi-parameter relative sensitivity analysis and single-parameter sensitivity analysis to obtain the optimal intervals of the composite tape winding process. First, the global multi-parameter sensitivity analysis method was applied to investigate the sensitivity of each parameter in the tape winding processing. Then, the local single-parameter sensitivity analysis method was employed to calculate the sensitivity of a single parameter within the corresponding range. Finally, the stability and instability ranges of each parameter were distinguished. Meanwhile, the authors optimized the process parameter ranges and provided comprehensive optimized intervals of the winding parameters. The verification test validated that the optimized intervals of the process parameters were reliable and stable for winding products manufacturing.

Система регулирования натяжного устройства при намотке изделий из композиционных материалов

Currently, products manufactured by the winding method, has found wide application in many industries. The use of modern management tools, the winding process requires the synthesis of controllers for tension taking into account the specific features of the process of. Known methods of synthesis do not take into account peculiarities of behavior of "wet" composite tape, as it passes through the non-rotating right-most path of the winding. In the article the technique of synthesis of regulators of the electric drives with the vector modulation control used in the winding of products

EXPERIMENTAL INVESTIGATIONS OF REINFORCED CONCRETE STRUCTURES OF HYDRAULIC STRUCTURES WITH BLOCK SEAMS, ENHANCED BY THE EXTERNAL REINFORCEMENT SYSTEM

A method of strengthening reinforced concrete structures by external reinforcement systems based on carbon fiber is widely used. Significant experience is accumulated in industrial and civil construction; there is also a certain experience of strengthening reinforced concrete structures of hydraulic structures. It was necessary to conduct experimental studies to justify technical solutions for strengthening the reinforced concrete structures of hydraulic structures. A characteristic feature of reinforced concrete structures of hydraulic structures is the mandatory availability of inter-block construction joints, which are caused by the need to build massive hydraulic structures with tiers and blocks with interruptions in concreting. Previously studies of reinforced concrete structures strengthened by composite materials were conducted without taking into account the block structure. The results of experimental studies of reinforced concrete beam structures of hydraulic structures reinforced with carbon strips having horizontal and vertical inter-block building seams are presented in the article. Experimental studies of a series of reinforced concrete beam-type models made of concrete of class B15 with longitudinal reinforcement from two bars. Their diameter is 10 mm and class is A500C (percentage of reinforcement 0.39%). The used concrete class is B25 with longitudinal reinforcement of three bars of diameter 12 mm and class A500C (percentage of reinforcement 0.84%). Their inter-block construction joints is before their strengthening and after reinforcement by longitudinal and transverse carbon composite tapes. In this case, a special type of cracking was recorded, in which cracks propagate along vertical and horizontal inter-block building seams. Due to the strengthening of reinforced concrete structures with carbon composite strips, the strength of the structures has increased, on average, by 1.78 times.

Optimizing the lay-up of composite tapes based on improved geodesic strategy for automated tape placement

The use of composite materials in aerospace, automotive and ship industry allows manufacturing lighter and more efficient mechanical structures. The major limiting factors are the high-manufacturing costs and low-production rates. Automated tape placement is one alternative process to overcome the limiting factors. Due to the complex contour of the mandrel, the lay-up paths of the contiguous tapes are not parallel along their lengths, which eventually introduce gaps or overlaps between the edges of tapes. Overlaps and excessive gaps are undesirable as they will decrease the strength of the resulting composite member. In this paper, a novel trajectory planning method for automated tape placement, entitled improved geodesic strategy, is proposed. The strategy aims to optimize the relationship between adjacent tapes. At the same time, the distortion of composite tape is also specified in order to prevent wrinkling. The principle and characteristic of the algorithm are presented. The method is investigated on the airfoil of an unmanned aerial vehicle and some of the results are presented in this paper.

Modeling and Simulation of Voids in Composite Tape Winding Process Based on Domain Superposition Technique

The tape winding technology is an effective way to fabricate rotationally composite materials. Nevertheless, some inevitable defects will seriously influence the performance of winding products. One of the crucial ways to identify the quality of fiber-reinforced composite material products is examining its void content. Significant improvement in products’ mechanical properties can be achieved by minimizing the void defect. Two methods were applied in this study, finite element analysis and experimental testing, respectively, to investigate the mechanism of how void forming in composite tape winding processing. Based on the theories of interlayer intimate contact and Domain Superposition Technique (DST), a three-dimensional model of prepreg tape void with SolidWorks has been modeled in this paper. Whereafter, ABAQUS simulation software was used to simulate the void content change with pressure and temperature. Finally, a series of experiments were performed to determine the accuracy of the model-based predictions. The results showed that the model is effective for predicting the void content in the composite tape winding process.

Transport current density at temperatures up to 25 K of Cu/Ag composite sheathed 122-type tapes and wires

The fabrication of iron-based superconductors with high transport critical current density (Jc) and low cost is a crucial determinant of whether they can be used for practical applications. In this paper, Cu/Ag composite sheathed Sr0.6K0.4Fe2As2 (Sr122) tapes and Ba0.6K0.4Fe2As2 (Ba122) round wires were fabricated via an ex situ powder-in-tube method and heat-treated by the hot pressing and hot isostatic pressing process respectively. In order to thoroughly reveal the application potential of Cu/Ag composite sheathed ‘122’ iron pnictide superconductors, transport Jc of tapes and wires in high fields at temperatures up to 25 K was measured. High transport Jc of 4.4 × 104 A cm−2 at 4.2 K and 3.6 × 103 A cm−2 at 20 K in 10 T was achieved in Cu/Ag composite sheathed Sr122 tapes. Transport Jc of Ba122 wires is 9.4 × 103 A cm−2 at 4.2 K and 1.9 × 103 A cm−2 at 20 K in 10 T. These results demonstrate the great potential of Cu/Ag composite sheathed ‘122’ iron pnictide superconducting tapes and wires for high-field applications at intermediate temperatures around 20 K, which can be easily obtained by using cryocoolers.

Wavelet Analysis of Acoustic Emissions during Tensile Test of Carbon Fibre Reinforced Polymer Composites

The increase of the interest in polymer composites in technology and in people’s everyday lives has been noticed in the recent years. Producing new materials with polymer matrix of particular properties that cannot be achieved by traditional construction materials contributed to high interest in fibre composite materials. However, a wider use of these materials is limited because of the lack of detailed knowledge about their properties and behaviour in various conditions of exposure under load. Mechanical degradation of polymer composites, which is caused by prolonged permanent loads, is connected with the changes of the material structure that are local or that include the whole volume of the element’s body. These changes are in the form of various types of discontinuity, including: deboning, matrix and fibers cracks and delamination. The article presents the example of the application of acoustic emission method based on the analysis of the waves through the use of wavelet analysis for the evaluation of the progress of the destructive processes and the level of the degradation of composite tapes that were subject to tensile testing.

Time-frequency analysis of acoustic emission signals generated by the Glass Fibre Reinforced Polymer Composites during the tensile test

Fibre reinforced polymer composites are currently dominating in the composite materials market. The lack of detailed knowledge about their properties and behaviour in various conditions of exposure under load significantly limits the broad possibilities of application of these materials. Occurring and accumulation of defects in material during the exploitation of the construction lead to the changes of its technical condition. The necessity to control the condition of the composite is therefore justified. For this purpose, non-destructive method of acoustic emission can be applied. This article presents an example of application of acoustic emission method based on time analysis and time-frequency analysis for the evaluation of the progress of the destructive processes and the level of degradation of glass fibre reinforced composite tapes that were subject to tensile testing.

Precision tension control technology of composite fiber tape winding molding

During the composite fiber tape winding process, tension fluctuation has a serious impact on the performance parameters of winding products, such as strength, compactness, resin content, fatigue resistance, and stress uniformity. Because of the influence of dynamic performance of tension control system caused by the torque motor, external disturbance, sensitivity of the parameter variation, inverter dead zone, ripple torque, cogging torque, nonlinear friction, and measurement noise, a fuzzy proportion integral derivative (PID) controller based on robust extended Kalman filter (REKF) is proposed, which considers membership function optimization of nonlinear dynamic fuzzy control system as systematic identification through designating activated membership function of input and output variable in each control step, and then, online adjustment of the activated membership functions is used to reduce the control error by REKF. By adjusting the shape and position of membership function, the designed controller can be adapted to the dynamic conditions. Simulation and experimental results show that overall performance of the control system has been significantly improved. Compared with traditional fuzzy PID, the fuzzy PID controller based on REKF has strong anti-interference performance and robustness, and the winding tension control precision has been increased by 40–42%.

An investigation of the effective parameters causing the critical current drop in a small high temperature superconducting D-shaped coil

In this paper, the dependency of the critical current on the magnetic field, temperature, and different curvature radii for a specific sample of Bi-2223/AgMg composite tape are investigated. By using this superconducting tape, a D-shaped pancake coil is designed and built. The coil critical current degradation at liquid nitrogen temperature with respect to a straight short sample of the same tape is reported, and also the portion of the bending and self-field contribution in the critical current drop is indicated separately. The hysteresis behavior as a function of the current rate during ramp up and ramp down cases on the voltage-current curve at liquid nitrogen temperature is examined. In addition, the quenching propagation speed is measured at two different radii of curvature of the designed magnet.