20 results about "Composite propeller" patented technology

The invention discloses a self-calibration strain test system and method for a propeller composite material, and solves the problems of high-precision measurement and real-time calibration of dynamic strain in a complex flow field environment. The core of the system comprises a linear fiber grating sensor array attached to the surface of a blade and an optical fiber demodulator integrated on a propeller hub, sensors are symmetrically arranged in the spanwise direction, and infrared transmitting / receiving devices in pairs intersect at the circle center O of the propeller hub when positioning is accurate, so that a global reference is formed; a single sensor is installed through a double-shaft flexible hinge, a shape memory alloy (SMA) wire driving mechanism is integrated, and spanwise / chordwise independent micro-motion calibration can be achieved according to infrared intersection point offset. A failure alarm is arranged in the sensor, gallium-indium-tin alloy is filled in hollow glass beads, alarm is triggered only when more than or equal to 3 beads are broken to form a conductive path, false alarm is avoided, and the problem of dynamic strain monitoring of the large-deformation composite propeller in high-pressure, low-temperature and strong-electromagnetic-interference environments is solved through the anti-electromagnetic-interference module.

The present application belongs to the field of structural optimization design, and specifically discloses an aerodynamic and structural optimization method for high-altitude adaptive deformation composite propellers, including establishing a composite propeller ply optimization model and initializing the model's design variables; establishing a serialized regional fiber sub-model of the composite propeller ply optimization model, and performing optimization operations in the serialized regional fiber sub-model; reading the output data of the composite propeller ply optimization model through simulation software to obtain the allowable strain of the composite material, the pitch angle at the design point, and the minimum number of regional plies; using the optimization objective function set by the serialized regional fiber sub-model for the allowable strain, the pitch angle at the design point, and the minimum number of regional plies, iteratively optimize the algorithm according to the set number of individuals in the population and the number of iterations, until the iteration is completed and the optimal individual for ply optimization is output. The structural optimization of high-altitude propellers can be achieved through the present application.

The rigid-flexible composite propeller hub connecting device for the variable pitch propeller comprises a propeller hub and a propeller root assembly, and is characterized in that a flexible connecting assembly is arranged at the connecting interface of the propeller hub and the propeller root assembly. The assembly is composed of rigid inner and outer ring bushings and a rubber elastomer embedded between the rigid inner and outer ring bushings. The inner ring lining is in close contact with the propeller root, and the outer ring lining is in interference fit with the propeller hub. By means of the rigid-flexible composite structure, reliable and accurate transmission of torque and centrifugal force is ensured, meanwhile, vibration energy generated by working of the propeller is effectively absorbed and dissipated through the high-damping rubber material, and therefore a vibration transmission path is remarkably blocked, the excellent vibration and noise reduction effect is achieved, and the working stability and reliability of a system are improved; and the service life of the propeller is prolonged. The variable-pitch propeller is compact in structure, convenient to assemble and maintain and easy to integrate into an existing variable-pitch propeller structure.

The invention relates to the technical field of composite propellers, in particular to a composite propeller blade foam filling area anti-deformation structure which comprises a first transverse crack arrest belt, a second transverse crack arrest belt and a reinforcing belt, the first transverse crack arrest belt is arranged on the surface of a foam filling area, and the second transverse crack arrest belt is arranged on the surface of the foam filling area; the inner edge of the end face of the foam filling area extends to the outer edge of the end face and then extends to the side face of the foam filling area; the second transverse crack arrest belt is arranged on the surface of the foam filling area, extends to the outer edge of the end face from the inner edge of the end face of the foam filling area and then extends to the side face of the foam filling area; the reinforcing band is arranged on the surface of the foam filling area and covers the first transverse crack arrest band and the second transverse crack arrest band. By arranging the first transverse crack arrest belt and the second transverse crack arrest belt, expansion of deformation of the foam filling area can be effectively prevented, the crack arrest belts are covered with the reinforcing belts, the overall strength and stability of the structure are further enhanced, and the deformation probability of the foam filling area is greatly reduced.

The application provides a device and method for fine measurement of a composite propeller blade deformation field. The device comprises an adjustable height horizontal control console, a horizontal plate, a blade loading point fixing device, a plurality of adjustable length displacement calibration probes, an electronic vernier caliper and a base device, and the like. The measurement method provided by the application realizes fine measurement of the blade deformation field of a composite propeller, can accurately, stably, efficiently and at low cost measure the small deformation amplitude of the composite propeller, thereby providing accurate test data support for simulation calculation, and can be applied to deformation measurement of composite propellers of different types and different scales.

The invention discloses a test method for testing the hydrodynamic performance of a composite propeller, and relates to the technical field of propeller performance test.The method comprises the steps that geometric similar conditions of a composite model propeller and a composite real propeller under the hydrodynamic load effect are determined; manufacturing a composite material model paddle according to a model scale ratio and arranging the composite material model paddle in a test water cylinder; according to the multiple groups of real-scale working condition parameters in combination with a model scale ratio, determining multiple groups of different test working condition parameters under the condition that geometric similarity conditions, motion similarity conditions and dynamic similarity conditions are met; performing an open water test according to each group of test working condition parameters, obtaining hydrodynamic performance parameters of the composite material model paddle, and fitting to obtain an open water characteristic curve; and determining the hydrodynamic performance of the composite material solid paddle based on the open water characteristic curve. According to the method, test conditions and test working conditions for testing the hydrodynamic performance of the composite propeller are given, and the accuracy of a hydrodynamic performance test result of the composite propeller is effectively improved.

This invention discloses a method for machining metal connectors for large composite propellers. Specifically, the method involves removing the cap of a casting to obtain a blank; welding positioning base points onto the surface of the blank; determining the coordinate values ​​and machining allowances for each positioning base point; rough machining of the blank; aging treatment before semi-finishing and determining the semi-finishing allowance; semi-finishing the blank; aging treatment before finishing and determining the finishing allowance; non-destructive testing; finishing the blank; machining the concave surface and the screw holes on both sides; countersunk hole machining; and machining the A and B end faces. By creating a clamping fixture, the blank is tightly fitted during machining, facilitating clamping and alignment. During rough machining, a reference plane is machined and positioning pin holes are bored and milled, serving as the alignment reference for subsequent semi-finishing and finishing, thus improving machining accuracy. This machining method can be widely applied to the manufacture of various connectors between propeller hubs and blades, improving machining accuracy and enabling product interchangeability, thus facilitating mass production.

The present invention relates to a damage identification method for composite propeller blades of a large unmanned aerial vehicle propulsion system, comprising: establishing multiple finite element material models, setting multiple sensor measurement points on each finite element material model, and constructing a transmissibility function between the sensor measurement points to obtain a marginal probability density function of each transmissibility function; obtaining a damage characteristic vector and a damage index corresponding to each finite element material model based on the marginal probability density functions of the multiple finite element material models; obtaining a damage judgment threshold based on the damage index, and obtaining a damage identification model based on the damage characteristic vector and a damage position in a damage model; obtaining a transmissibility function to be measured between the sensor measurement points on the blade to be measured, and obtaining a damage index to be measured and a damage characteristic vector to be measured based on the transmissibility function to be measured; judging whether the damage index to be measured exceeds the damage judgment threshold, and if so, obtaining the damage position based on the damage identification model.

The application discloses a self-calibration strain testing system and method for propeller composite materials, and solves the problems of high-precision measurement and real-time calibration of dynamic strain under a complex flow field environment. The system core comprises a linear fiber grating sensor array attached to the surface of the propeller blade and a fiber demodulator integrated in the propeller hub. The sensors are arranged symmetrically along the span, and two infrared transmitting / receiving devices in each pair intersect at the center O of the hub to form a global reference when positioned accurately. A single sensor is installed through a double-shaft flexible hinge and integrated with a shape memory alloy (SMA) wire driving mechanism, which can realize independent micro-motion calibration in the span direction and the chord direction according to the offset of the infrared intersection. The sensor is provided with an internal failure alarm, which is filled with gallium-indium-tin alloy through hollow glass microbeads. The alarm is triggered only when >= 3 microbeads are broken to form a conductive path, thereby avoiding false alarms. The anti-electromagnetic interference module solves the problem of dynamic strain monitoring of the large-deformation composite propeller under high pressure, low temperature and strong electromagnetic environment.

This invention relates to the field of composite material propeller blade molding technology, and discloses a large-size composite material propeller blade molding mold, comprising: a blade, a base mold, and a connecting section assembly mold. The base mold is located below the blade, and one side of the base mold has a product film-coating surface. The connecting section assembly mold is located above the base mold, and includes a top mold, a side wall mold below the top mold, and a fastening mold on the side of the side wall mold away from the top mold. This invention, through the combination of a base mold, a connecting section assembly mold, and a prepreg vacuum bag compression molding process, produces large-size composite material propeller blades with low cost, high quality, and high performance. The product has a compact structure, low porosity, high fiber straightness, and excellent performance. It also has the advantages of a clear and simple production process, low equipment requirements, convenient and quick mold operation, and strong feasibility.

The application belongs to the technical field of composite propeller analysis, and particularly relates to a composite propeller excitation characteristic test method based on finite element optimization. The method comprises the following steps: based on the propeller type value, completing the parametric expression of the propeller and the finite element grid processing; simulating and calculating the propeller excitation characteristic to generate the excitation configuration parameters required for actual measurement; selecting the propeller simulation excitation point according to the propeller simulation mode and the excitation characteristic obtained in steps A and B; establishing a data acquisition system for measuring the excitation response signal; based on the data acquisition system and the excitation configuration parameters, performing the excitation test to obtain the excitation response signal of all the excitation points; the application is convenient for quickly generating and optimizing the test configuration scheme, and then the inherent vibration characteristic of the propeller is measured by using the excitation device, so that the excitation characteristic is determined, thereby laying a foundation for the production and development of a low-noise pre-deformation composite propeller.

Lightning strike protection for composite propellers is provided by a bonding tab assembly which is electrically bonded to an electrically conductive protective band fixed to a leading edge of the composite propeller blade. The bonding tab establishes an electrically conductive path for a lightning strike on the protective band to be directed to the propeller hub thereby providing lightning strike protection to the propeller. The bonding tab assembly may include a mounting bracket having a lower mounting flange and an upright mounting plate, the lower mounting adapted to being attached to a counterweight clamp attached to a metallic blade collar surrounding the propeller blade shank. A bonding tab is attached to the upright mounting plate of the mounting bracket and adapted to being brought into spring-biased contact with a portion of the protective metal band affixed to the leading edge of the composite propeller blade.

The invention belongs to the technical field of manufacturing of composite propeller guide pipes for ships, and particularly discloses a forming method of a hollow reinforced permeable structure composite propeller guide pipe. According to the forming method, the stator is prepared through an integrated forming process, the forming process is optimized, and the continuity and the connection strength of a cloth layer are improved; the OOA process is divided into an upper part and a lower part for respectively forming the skin, so that the problem of unstable forming quality of the outer skin in the traditional process is solved; except for the rib plate and the flat plate, other parts are all formed in a net size mode, and machining procedures and machining cost are reduced; and moreover, the OOA process is adopted to realize pressurized curing, so that the compactness of fibers in the composite material outer skin is increased, the porosity of the outer skin is reduced, the phenomena of outer surface pits, paint layer bumps and the like after a pressure test are solved, and the use pressure of the product is improved. The forming method solves the technical barriers that an existing forming method is low in production efficiency, high in cost and unstable in quality, and has the advantages of being low in cost and high in quality.

The invention discloses an integral type composite material propeller torque testing device which comprises a bottom plate, a first side plate and a second side plate are fixedly connected to the two sides of the bottom plate respectively, a rotating torque shaft is installed between the first side plate and the second side plate, a plurality of check blocks are fixedly connected to the inner side of the second side plate, and the check blocks are matched with blades of a propeller; the force arm connecting rod is provided with a force loading rod, the force loading rod is axially perpendicular to the force arm connecting rod, the two ends of the force arm connecting rod are both connected with torque loading arms, and the ends, away from the force arm connecting rod, of the two torque loading arms are assembled with the two ends, extending out of the first side plate and the second side plate, of the rotating torque shaft correspondingly. And the two torque loading arms are respectively positioned on the outer sides of the two side plates. The integral type composite material propeller torque testing device is simple in structure, greatly saves equipment, labor and time cost, and solves the problem that a loading device cannot simulate stress of blades in water due to mutual shielding of the blades of an integral type propeller.

The invention belongs to the technical field of ship propeller test analysis equipment, and particularly relates to a composite propeller underwater vibration characteristic measurement test device and a measurement method thereof. Comprising a fixed base fixed underwater, a paddle supporting seat mounted at the top of the fixed base, a longitudinal cutting propeller hub fixed at the front side of the paddle supporting seat, paddles arranged at the front side of the longitudinal cutting propeller hub, an acceleration sensor arranged at a vibration pick-up point of the paddles, and a vibration excitation device arranged right above a vibration excitation point of the paddles; according to the test device and method for measuring the underwater vibration characteristics of the composite propeller of the real ship, the acceleration sensor and the data collecting and processing system are used for collecting and recording excitation signals of excitation points and response signals of vibration pick-up points of the blade, and simulation of vibration modes and inherent frequencies of the blade in all orders of modes underwater is combined; the vibration characteristics such as the underwater modal shape, the inherent frequency and the modal damping of the composite propeller blade of the real ship are obtained, and a test foundation is laid for analyzing the underwater inherent characteristics and low-noise pre-deformation design of the composite propeller blade.

The application discloses a small composite propeller and a preparation method thereof. The small composite propeller comprises a metal part and a composite part. The metal part is an inner ring part of a hub. The composite part is an integral structure, comprising an outer ring part of the hub and all blades. The outer wall of the metal part is provided with a plurality of protrusions or grooves for forming an interlocking connection with the composite part. The composite part is integrally injection molded by embedding the metal part into an injection mold. Based on the interface characteristics of the composite part and the metal part, the connection structure is innovatively designed. The integral design of the circumferential structure of the composite part ensures the strength reliability of the connection between the metal part and the composite part. The manufacturing is completed by integral injection molding, which is high in manufacturing efficiency, low in manufacturing cost, and short in single-piece manufacturing period (within 8 minutes). The manufacturing cost advantage is more obvious in the case of large batch molding demand.

The application belongs to the technical field of robots, and discloses an amphibious robot propulsion device and method based on a wheel-propeller composite structure. The device is integrated with a reduction motor driving system of a wheel mechanism and a composite propeller system of a propeller mechanism, and outputs propulsion power in the same coaxial direction. The reduction motor driving system takes a waterproof reduction motor as a driver to provide power for the amphibious robot when walking on the ground. The composite propeller system takes a propeller as a driving component to provide power for the amphibious robot when floating in water. The application can interact with other structures to form vector propulsion, increase controllability and stability of the robot, and quickly switch between water and land modes. The switching structure is simple. Most amphibious robot water-land switching structures are too complex, which causes great pressure on the body space and reduces the practicability of the product.

The invention relates to a design method of a blade middle surface layer-propeller hub integrated metal embedded composite material propeller, which comprises the following steps: constructing a blade middle surface layer-propeller hub integrated metal embedded composite material propeller integral structure, the structure comprises an integrated high-rigidity area made of metal and a carbon fiber composite material layer wrapping the integrated high-rigidity area. The propeller is divided into a limited number of areas with similar shapes in the radial direction, and the areas are segmented and discretized into fiber metal laminated variable cross-section beams with similar limited section widths; based on a classic laminated plate theory and metal plastic mechanics, acquiring a stiffness parameter of the fiber metal laminated variable cross-section beam through a multi-scale hybrid analysis method; a series spring model is adopted, the variable cross-section beams in the similar areas of the same shape are connected in series and stacked, and then stacking results of all the areas are combined to obtain the overall effective rigidity of the propeller; and according to the overall effective rigidity result, the laying sequence and interlayer ratio of the metal layers and the composite material layers are designed.

The invention discloses a composite material propeller blade structure and a manufacturing method thereof. The composite material propeller blade structure comprises a supporting pipe; the girder layer comprises a middle girder, a front edge girder and a rear edge girder; the skin layer comprises a first skin, a second skin and a third skin; the threaded sleeve is arranged on the outer side of the first skin, and external threads are arranged on the outer side of the threaded sleeve; the cloth liner layer is arranged on the outer side of the first skin; and the metal pipe fitting is used for being connected with a propeller hub and is in threaded connection with the threaded sleeve. According to the invention, the blades made of the composite material are arranged and are cured to form a whole body, so that firm interface bonding is formed, loads are effectively transmitted, stress concentration is avoided, the propeller can be suitable for low-rotating-speed and large-load electric vertical take-off and landing aircrafts, and the structural weight is reduced and the reliability is improved while the connection reliability is ensured.

This application relates to an RTM mold structure for composite material propeller blades, including an upper mold, a lower mold, and a sealing strip. The upper mold has a protrusion protruding from the parting surface, and a first mold cavity matching the upper contour of the blade is formed on the inner side of the protrusion. The lower mold has a recessed portion recessed into the parting surface, and a second mold cavity matching the lower contour of the blade is formed on the inner side of the recess. After the lower mold and the upper mold are engaged along the parting surface, the first mold cavity and the second mold cavity are joined to form a complete mold cavity for molding the propeller blade. The sealing strip is disposed on the contact side of the recessed portion and the protrusion. The upper mold is a protrusion protruding from the parting surface, and the lower mold is a recessed portion recessed into the parting surface. The lower mold aligns with the upper mold to form a circumferential limit. Compared with the traditional guide post and guide sleeve positioning method, the positioning accuracy is greatly improved, effectively preventing the relative displacement of the upper and lower molds during pressurization and heating, and ensuring the accuracy of the blade shape. At the same time, the sealing strip is disposed on the contact side of the recessed portion and the protrusion, replacing the traditional parting surface sealing structure, resulting in a more stable sealing effect.