Research On The RTM Process Of Aeroelastic Model Of Wing And Mold Design

It’s significant to verify and revamp the design for increasing the design reliability through manufacturing the aeroelastic model of wing. Wing model is mainly composed of longitudinal beam,transverse rib, skin and joints. The skin was traditionally manufactured by hand lay-up process, which is inefficient and harmful to worker’s health and environment by volatiling a large number of harmful gas. Resin transfer molding process is a kind of advanced liquid composite molding process, in addition to overcoming the traditional shortcomings, high dimensional accuracy and surface quality product can be obtained through this process, thus it’s used to fabricate wing model gradually in recent years. Because of the complexity of the structure of wing, it make a lot of sense to study the mold, the design and fabrication of preform,and the process parameters.The mould design level has a great affect on dimensional accuracy and surface quality of product. Mould design based on numerical simulation can improve the design efficiency significantly, reduce the cost of mould manufacturing and improve the quality of the parts. Permeability is one of the key input parameters. It is of great significance to obtain reliable permeability value of reinforced material for improve the reliability of flow simulation. The theory of reinforced material permeability prediction and experimental measurement method are stated, one dimensional unidirectional flow and two-dimensional radial flow are carried out for the measurement of permeability under2,4,6,8layer fiber,and the apparent permeability of fiber is obtained finally. Experiment results reveal that the apparent permeability value decrease with the increase of the number of fiber layer, and permeability measured by radial flow experiment is greater than the value measured by one dimensional unidirectional flow experiment.The arrangement of gate and vent is a critical factor influencing the resin flow pattern in the fiber, the optimization of arrangement of gate and vent is conducted in this paper. The resin flow in the cavity is simulated by numerical software, and a process performance index that evaluate the arrangement of gate and vent is proposed combined with the practice. Some conclusion can be made by conducting the simulation of setting schemas:molding filling time became shorter and the weld mark is longer with the increase of the number of gate. The number of vent is not relevant obviously with the number of gate; It is necessary to set vent near the embedded part under the condition that preform contains embedded parts, and its size can not be neglected, and it is far away from gate; Constant pressure injection is more reasonable than employing either solely.The best schema which characterized by optimal process performance index is obtained by flow simulation, according which the arrangement of gate and vent is determined. In addition, the overall structure of mould and the seal structure are designed effectively for conducting the flow experiment and manufacturing qualified wing model.