Robotized Filament Winding Research Articles

Performance index of isogrid structures: robotic filament winding carbon fiber reinforced polymer vs. titanium alloy

ABSTRACT The structures adopted in the aeronautic field should have three main characteristics: they must be strong, stiff, and light. These targets can be obtained by choosing high performance and low weight materials, as composite or titanium alloy, but also the wise design of the structure itself is important for enhancing the mechanical performances. The isogrid structures, that are composed of a lattice frame reinforcing a skin, represent a very interesting solution to fulfill the abovementioned requirements. In the present work, a comparative analysis of the structural performances of lattice-stiffened cylinders made of different materials was carried out. The studied parts were made of carbon fiber composite material or titanium alloy, while a FEM model was implemented and verified for this study. The cylinder made of composite material was produced through robotic filament winding, an innovative technology that allows the attainment of high-quality parts. It was found that the strength and the stiffness of the structures were almost the same for both the analyzed material, but very interesting results were determined by considering the weight of the different structures: the composite material one resulted to be the most performant since it had the highest specific performances.

A Non-Geodesic Trajectory Design Method and Its Post-Processing for Robotic Filament Winding of Composite Tee Pipes.

With the advantages of high specific strength and well corrosion resistance, polymer-matrix composite tee pipes are widely used in aerospace and civilian fields. The robotic filament winding technology is suitable for forming complex shape parts. This paper aims to provide a novel non-geodesic trajectory design method to get a continuous trajectory for tee pipe winding. Furthermore, post-processing methods are proposed for realizing the full coverage of tee pipes by robotic filament winding. The CAD/CAM software is then designed to simulate the winding process and realize the cover of the whole tee pipe. Finally, experiments of winding a tee pipe with a desktop winding machine and a six-axis winding robot are carried out. The results show that the tee pipe is fully covered, verifying the accuracy of the design method and post-processing methods.

Axial and Radial Compression Behavior of Composite Rocket Launcher Developed by Robotized Filament Winding: Simulation and Experimental Validation.

The principal objective of the work is to compare among carbon-glass filament wound epoxy matrix hybrid composites with a different fiber ratio made by robotized winding processes and optimize the geometry suitable for the Rocket Propelled Grenade Launcher. ANSYS based finite element analysis was used to predict the axial as well as radial compression behavior. Experimental samples were developed by a robot-controlled filament winding process that was incorporated with continuous resin impregnation. The experimental samples were evaluated for the corresponding compressional properties. Filament wound tubular composite structures were developed by changing the sequence of stacking of hoop layers and helical layers, and also by changing the angle of wind of the helical layers while keeping the sequence constant. The samples were developed from carbon and glass filaments with different carbon proportions (0%, 25%, 50%, 75%, and 100%) and impregnated with epoxy resin. The compressional properties of the tubular composites that were prepared by filament winding were compared with the predicted axial and radial compressional properties from computational modelling using the finite element model. A very high correlation and relatively small prediction error was obtained.

Robotic filament winding: An innovative technology to manufacture complex shape structural parts

The robotic filament winding (RFW) technology consists of an industrial robot that is equipped with a feed and deposition systems; they are suitable for placing a tape along the stress directions the part is subjected to during operation. RFW cell replaces the human operator that is the only system that has been previously used to manufacture complex shape parts. It represents an advantage as regards process control, repeatability and manufacturing times. The present work focuses on the family of structural parts whose shape may be obtained as a result of a full section sweeping along a closed non auto-intersecting 3D curve. The aim of the paper is to present a design methodology for the forming process of complex shape structural parts by RFW, in order to obtain structural homogeneity and fibre content uniformity, and so to demonstrate the potential of an innovative robotic cell for manufacturing these parts.

Manufacture of high performance isogrid structure by Robotic Filament Winding

Aeronautical and aerospace industries require light and robust structures. This target can be achieved designing isogrid structures made of composite material. In fact, such structures present both lightness and structural resistance. However, some problems can arise during the manufacturing process of these structures. In the present work the RFW (Robotic Filament Winding) technology is used for manufacturing an isogrid cylinder, made of composite material. The work was carried out in different steps. In the first, a suitable deposition head for fibres stratification was designed, then it was utilized to manufacture isogrid structures. Finally, both geometrical and structural tests were carried out on these structures and their results were compared with those one obtained from handmade structures. The comparison highlighted a better quality of the RFW structures. In fact, these structures complied with the geometrical tolerances, presented a lower void content and exhibited a higher resistance to axial compression load.

Fibrous structures: An integrative approach to design computation, simulation and fabrication for lightweight, glass and carbon fibre composite structures in architecture based on biomimetic design principles

In this paper the authors present research into an integrative computational design methodology for the design and robotic implementation of fibre-composite systems. The proposed approach is based on the concurrent and reciprocal integration of biological analysis, material design, structural analysis, and the constraints of robotic filament winding within a coherent computational design process. A particular focus is set on the development of specific tools and solvers for the generation, simulation and optimization of the fibre layout and their feedback into the global morphology of the system. The methodology demonstrates how fibre reinforced composites can be arranged and processed in order to meet the specific requirements of architectural design and building construction. This was further tested through the design and fabrication of a full-scale architectural prototype.

Robotized Filament Winding of Full Section Parts: Comparison Between Two Winding Trajectory Planning Rules

Robotized filament winding technology involves a robot that winds a roving impregnated by resin on a die along the directions of stresses to which the work-piece is submitted in applications. The robot moves a deposition head along a winding trajectory in order to deposit roving. The trajectory planning is a very critical aspect of robotized filament winding technology, since it is responsible for both the tension constancy and the winding time. The present work shows two original rules to plan the winding trajectory of structural parts, whose shape is obtained by sweeping a full section around a 3D curve that must be closed and not crossing in order to assure a continuous winding. The first rule plans the winding trajectory by approximating the part 3D shape with straight lines; it is called the discretized rule. The second rule defines the winding trajectory simply by offsetting a 3D curve that reproduces the part 3D shape, of a defined distance; it is called the offset rule. The two rules have been compared in terms of roving tension and winding time. The present work shows how the offset rule enables achievement of both the required aims: to manufacture parts of high structural performances by keeping the tension on the roving near to the nominal value and to markedly decrease the winding time. This is the first step towards the optimization of the robotized filament winding technology.

Actual Safety Distance and Winding Tension to Manufacture Full Section Parts by Robotized Filament Winding

Robotized filament winding technology allows one to manufacture workpieces of high performances as a result of a robot placing fibers impregnated by resin (known as roving) along the directions of stresses the workpiece is subjected to in exercise; thus, robotized filament winding favors rigidity and strength of a workpiece along some preferential directions. A proper value of the winding tension has to be chosen and kept constant along the whole winding in order to limit the defects inside the composite workpieces. To keep the tension value on roving near to the nominal value, one must plan the value of the geometric parameters characterizing the winding trajectory. The same geometric parameters influence the value of the actual safety distance that may involve collisions among the deposition system and the components of the robotized cell. This work shows how to avoid the occurrence of collisions by planning the value of the actual safety distance through the definition of geometric parameters that characterize the winding trajectory. Moreover, the collision occurrence should be considered together with the control of the winding tension on the roving in the robotized filament winding planning stage. The present work shows how to solve both the problems previously defined (i.e., to keep the winding tension on roving near to the nominal value and to avoid collision occurrence), by the solution of a constrained optimization system.

Winding Trajectory and Winding Time in Robotized Filament Winding of Asymmetric Shape Parts

Robotized filament winding is a technology to deposit a roving on a die according to a planned robot trajectory and to polymerize the wound part in a furnace for thermoset resin matrix. In this way, it is possible to wind asymmetric or complex parts. The winding trajectory is a critical aspect of the robotized filament winding process, since the mechanical performances and the winding time of the manufactured composite part change according to winding trajectory geometry. The present work discusses original criteria for the determination of a proper winding system trajectory and its influence on the winding time. This work studies the influence of the geometric parameters, that characterize the trajectory covered by the deposition system to wind the roving on the die, on winding time. The obtained results may help to identify the values of the geometric parameters that minimize the winding time and, at the same time, that keep constant the winding tension in order to assure an acceptable quality of composite parts. This work represents the first step to optimize the planning of the winding trajectory.

Influence of winding speed and winding trajectory on tension in robotized filament winding of full section parts

When composite parts are manufactured by robotized filament winding technology, winding tension is a very important parameter to be controlled since it influences directly the defects and the mechanical property of these parts. The present work aims to study the influence of the main winding parameters on tension during the manufacturing of full section composite parts. In particular, the focus of this work is to determine both the geometric parameters characterizing the winding trajectory and the winding speed that allows to keep the winding tension near to the nominal value that has been planned to have good composite parts. The geometric parameters of the winding trajectory are the number of points used to approximate the winding trajectory, the trajectory angle and the distance of the deposition system from the winding die in order to avoid collisions (called safety distance). The conclusions developed in this work may be used to understand the change in tension average value of winding typology.

Estimation of the winding tension to manufacture full section parts with robotized filament winding technology

Winding tension is a very critical parameter to be controlled during the manufacturing of composite parts by robotized filament winding technology. In fact, the winding tension influences directly the defects and the mechanical properties of composite parts.The nominal value of the winding tension that has been set in order to obtain a good roving alignment and compactness inside the composite part is not equal to the actual value acting on roving during the winding. The difference between the nominal and actual value of the winding tension is due both to the typology of the winding trajectory that has been set and to the agents that are external to the technological process and consequently hardly controllable. Therefore, once the value of the nominal winding tension has been set and the geometry of the part to be wound has been fixed, it is necessary to act on the geometric parameters of the winding trajectory in order to guarantee that tension acting on the roving during the winding is as near as possible to the nominal value. The present work shows how using a unique parameter, the actual trajectory angle characterizing the planned winding trajectory, it is possible to estimate quickly and easily the average value of the tension acting on the roving once the nominal winding tension and the geometry of the part to be wound have been chosen. In this way it is possible to decide which winding trajectory typology is prefereable in order to manufacture a composite part of good quality.

Method to Evaluate Winding Trajectories in Robotized Filament Winding

Robotized filament winding technology involves the deposition of a tape according to a planned robot trajectory and its polymerisation in a furnace for thermoset resin matrix. In this way it is possible to wind asymmetric or complex parts. The winding trajectory is a critical aspect of the robotized filament winding process, since the mechanical performances and the winding time of the manufactured composite part change according to winding trajectory geometry. This work presents an original method to optimize and to compare alternative winding trajectories for robotized filament winding. The proposed method uses a set of geometric parameters that characterize the winding process and, in the same time, that are easy to measure. Therefore, the implemented method is quick and user friendly. The designed method has been implemented and tested on two different trajectories that have been planned to wind a same composite part.

Conceptual design of robotic filament winding complexes

Filament winding is one of the most efficient techniques in the manufacture of engineering components from fiber reinforced composite materials. It provides precise distribution of reinforcement into the weaker matrix material, and it lends itself to automation, taking advantage of the recent advances in mechatronics and robotics. A typical robotic filament winding complex (RFWC) integrates design, analysis and manufacturing. It features a specialized CAD/CAM software package for winding pattern generation and analysis of the part to be produced, a mechanical assemblage of winding and handling subsystems with the corresponding control. This paper reports an analysis of some notable existing RFWCs, primarily from the perspective of mechanical design. The conclusions following this analysis have led to the formulation of a novel concept for robotizing the process of winding asymmetric parts which is based on two manipulating devices, one mandrel manipulator and one payout tool carrier. The parameters that influence the conceptual design of RFWCs are discussed, including system configurations, the necessary and sufficient number of degrees of freedom and their distribution within the complexes. Emphasis has been given to process parametrization, structural synthesis and the design of a mandrel manipulator wrist. Two examples are cited to illustrate this new concept.

Computer-integrated filament winding: computer-integrated design, robotic filament winding and robotic quality control

A computer-integrated environment has been created around the filament winding process, including design, production and quality control. In the design phase, computer-aided design, finite element analysis and fibre path calculation techniques are integrated. Two filament winding machines have been developed for production: a two-axis filament winding machine and a robotic tape winding machine. The collision-free robot program is generated completely off-line. For quality control, a robotic ultrasonic C-scanning cell has been developed.