313 results about "Arc length" patented technology

The invention discloses a curve determination method for a centrifugal pump point-by-point integration method, and belongs to the technical field of centrifugal pumps. The curve determination method of the centrifugal pump point-by-point integration method is a parameterized modeling method based on an Euler equation and momentum conservation, the inlet and outlet boundaries of a vur curve are calculated according to design requirements, after a smooth transition curve is constructed in combination with runner geometry and attack angle constraint, the curve is constructed through nonlinear interpolation according to the dynamic correlation streamline arc length, and the curve is determined. The relation between the streamline arc length and the curve is established; according to the method, when the centrifugal pump blade molded line is designed, the curve can be quickly obtained through a parameterization method according to the given design condition and the streamline arc length s.

The invention discloses a five-axis machining tool path planning method for a complex curved surface, and relates to the technical field of numerical control machining. Subregions are divided based on the Gaussian curvature of a curved surface model, and a region equation is fitted; projecting the sub-regions and screening to obtain a boundary point set, fitting a curved surface equation by adopting cubic NURBS, and performing normal vector and curvature constraint optimization to splice an optimal curved surface equation; setting a section plane, calculating a section curve, calculating an arc length based on a Simpson formula, and planning a track point coordinate sequence according to the curvature; constructing a spiral equation of adjacent section planes, calculating a spiral step length based on a Simpson formula according to a position and tangent continuous constraint solving coefficient, and generating a cross-plane track point sequence; in the section plane, based on lossless and cutting direction constraints, an optimal angle sequence is obtained through optimization of a genetic algorithm, and a cross-plane angle sequence is obtained through cosine interpolation; and a machining pose sequence is generated through integration, and high-precision machining of the complex curved surface is achieved.

The invention relates to a wall-climbing laser cleaning robot weld joint identification tracking control method and device, and belongs to the technical field of robot tracking control. The maximum curvature of the arc length between the position point of the robot at the current moment and a preview point is determined, the maximum longitudinal speed corresponding to the maximum curvature is determined, and the preview point is any point on the weld joint track in the advancing direction of the robot; and determining a predicted position of the robot at the next moment according to the maximum curvature and the maximum longitudinal speed, and controlling the robot to move to the predicted position. The method solves the problem that the precision of a dynamical model and an operation control strategy of the wall-climbing robot is low because the wall surface motion control of the wall-climbing robot does not consider the influence of adsorption force and gravity.

Provided is a submerged arc welding method including: receiving setting of a gain indicating responsiveness of a variation in a feeding speed of a welding wire with respect to a variation in an arc length; detecting a welding voltage corresponding to the arc length; controlling the arc length by changing the feeding speed of the welding wire on the basis of the detected voltage, and controlling the arc length by changing the feeding speed of the welding wire on the basis of the detected voltage, a predetermined voltage corresponding to a predetermined arc length, and the received gain.

The invention belongs to the technical field of deep rock mass drilling coring, discloses a deep rock mass drilling large-curvature trajectory control method and device and a storage medium, and solves the problems that in the prior art, a generated drilling curve is not high in precision, and accurate drilling trajectory control cannot be carried out. According to the method, a drilling curve is described through a segmented Bezier curve, data such as path length, angle and depth in the actual drilling process are obtained, the error between the actual length of a minimum drilling path and the arc length of the corresponding Bezier curve is used as a target, iterative calculation is conducted on relative coordinates of a drill bit through an optimization algorithm, and the optimal drilling path is obtained. Therefore, the control points on the Bezier curve are accurately corrected, so that the Bezier curve infinitely approaches the real drilling track, the precision of the generated drilling curve is finally improved, the drilling direction of the drill bit is optimized and adjusted according to the drilling curve generated in real time, and the drilling track is controlled.

The invention provides a mountain slope transmission system catenary determining method and device, and the method comprises the steps: obtaining the arrangement parameters of a transmission system on a mountain slope, and the arrangement parameters at least comprise the horizontal distance between two fixed points of the transmission system, the vertical height difference, and the total length of a rope of the transmission system; based on the arrangement parameters, a simultaneous equation with the catenary opening coefficient as a core unknown quantity is established, and the simultaneous equation comprises the arc length constraint of the catenary and the height difference constraint of the two end points at the same time; solving the simultaneous equation to obtain a numerical solution of the catenary opening coefficient; and determining a catenary shape and a core engineering index of the transmission system on the mountain slope under the action of gravity according to the solved catenary opening coefficient. According to the method and the device, the engineering design precision is improved, and material redundancy and adjustment cost caused by shape uncertainty are saved.

The invention relates to the technical field of speed reducers, and particularly discloses a harmonic speed reducer rigid gear tooth profile design method which comprises the following steps: giving a polar coordinate expression of a flexible gear neutral layer curve: r = p / cos (mu); assuming that the rotation angle of the undeformed end of the flexible gear is # imgabs0 # in unit time, according to the assumption that a neutral layer curve is not elongated before and after deformation of the flexible gear, the arc length of the deformed end of the flexible gear is equal to the arc length of the undeformed end of the flexible gear, and according to the Cauchy formula of the convex set perimeter, # imgabs1 # Zc is the tooth number of the rigid gear, and Zf is the tooth number of the flexible gear; a parameter equation of the tooth profile of the rigid gear can be obtained according to the envelope theory, the tooth profile of one tooth in the rigid gear is obtained, and then the whole tooth profile of the rigid gear is obtained through the array. When the rigid gear calculated through the method is used in the three-wave speed reducer, the transmission ratio is smaller than 10, and the meshing area of the rigid gear and the flexible gear exceeds 40%.

The invention belongs to the technical field of flexible structure design, and particularly relates to a variable-arc-length arched beam structure which comprises a sliding groove section, a sliding key section, a corrugated beam, a variable-height supporting column and a variable-length supporting rod. The corrugated beams are arranged on the outer sides of the sliding key sections and the sliding groove sections and are provided with wave crest and wave trough structures; the sliding key sections and the sliding groove sections are located on the inner sides of the corrugated beams, arranged at intervals and distributed in a staggered mode. The corrugated beams, the sliding key sections and the sliding groove sections are all of arc-shaped structures, and wave crests and wave troughs of the corrugated beams are arranged in the radial direction of the arc-shaped structures; when the shape and the arc length of the arched beam are changed, the variable-height supporting columns and the variable-length supporting rods can automatically generate height changes, then the sliding key sections and the sliding groove sections are driven to relatively slide, and meanwhile the corrugated beams evenly distribute the arc length changes to the positions between the adjacent wave crests, so that external loads are evenly distributed to the arched beam. Therefore, the size of the fuselage is correspondingly reduced along with fuel consumption.

The invention provides a large-span beam formwork three-dimensional parameterization deepening design method, and belongs to the technical field of building construction.The method includes the steps that geometric parameters of a large-span beam three-dimensional parameterization model are obtained, and a multi-scale homogenization mechanical analysis model is established to describe nonlinear characteristics of a concrete material; an arc length control method is combined with a Newton-Raphson iterative improved algorithm to carry out large-deformation nonlinear analysis to calculate deformation control parameters, safety performance is evaluated, support structure parameters are adjusted, and a double-layer game optimization model is established to determine optimal template support system parameters. On the basis of a bending-torsion coupling analysis result, a force transmission path diagram is established through a load transmission path generation function, and an optimal force transmission path is determined by adopting a gradient optimization algorithm, so that the problems that the design of a large-span beam formwork supporting system lacks an accurate mechanical calculation basis, and structural deformation and stress distribution cannot be accurately predicted are solved; and the design of the supporting system is not reasonable.

The present invention belongs to the technical field of electrochemical machining, and particularly relates to a design method for the cathode profile of an all-metal oil screw drill stator by electrochemical machining. The contour curve of the cathode profile is designed into a dot matrix according to unequal gaps, so as to obtain the control points, order and knot vector of the contour curve, construct operators, and use integral spline operators to control the global shape of the contour curve to achieve rough fitting of the cathode contour; when the square curvature of the cathode contour curve is the smallest relative to the integral of its arc length, the curvature of the curve is the most uniform. A fitting index for the cathode contour curve is constructed, and the discrete curvature at each point of the cathode contour curve is calculated in turn to achieve precise fitting of the cathode contour curve, and the error can be controlled within the accuracy range of 0.002 mm; the "B-τ" spline inner contour integration method is used to design the cathode profile of the all-metal oil screw drill stator. The present invention has the advantages of short cathode design cycle, high forming accuracy, and significantly reduced cathode manufacturing cost.

The invention relates to the technical field of automatic welding, in particular to a high-strength austenitic stainless steel welding process characteristic curve making method which comprises the following specific steps: S1, selecting a welding process characteristic curve according to parameters corresponding to a common stainless steel weldment; s2, re-calibrating peak energy; s3, reformulating a pulse waveform; and S4, based on an arc length prediction formula of the pulse parameters and the wire feeding speed, calculating to obtain a base value current and a pulse frequency. According to the method, the pulse welding waveform is adjusted and optimized, the single pulse energy distribution in the welding process is modified, the pulse waveform special for the high-strength austenitic welding wire is formed, the special welding process characteristic curve customized for the high-strength austenitic stainless steel welding material is invented, and then the welding manufacturability and the molten pool spreadability of the high-strength austenitic stainless steel are optimized.

The utility model discloses a movable tubular pile gas shielded welding windshield which comprises a radius adjusting cover and a perimeter adjusting block, the radius adjusting cover is of an arc-shaped structure, the inner ring of the radius adjusting cover is attached and adsorbed to the circumferential outer wall of a tubular pile, and the outer ring of the radius adjusting cover is symmetrical and is connected with a welding gun rod in an elastic tensioning mode. Perimeter adjusting blocks are telescopically inserted into two circumferential end surfaces of the arc-shaped structure of the radius adjusting cover. The windproof cover is used for covering and protecting the flame of the welding gun, can adaptively adjust the local covering radius and arc length according to the diameter of a pipe pile, can move along with the movement of the welding gun, and is simple in structure and easy to implement.

The invention provides a railway carriage elastic bearing body detection tool, and belongs to the technical field of bearing body detection tools. Comprising a clamping mechanism, a supporting frame body is installed on the top of the clamping mechanism, a first frame body is arranged on one side of the clamping mechanism, a second frame body is arranged at the bottom of the clamping mechanism, side bearing boxes are installed on the two sides of the top of the first frame body, and side bearing bodies are installed on the tops of the side bearing boxes; and the first outer contour measuring mechanism is used for measuring the length and the width of the side bearing box. Through the arrangement of the first outer contour measuring mechanism and the second outer contour measuring mechanism, the length and width of the outer contour of the side bearing box and the arc length and curvature of the corners of the outer contour can be rapidly measured by using the first outer contour measuring mechanism; and the length and the width of the outer contour of the side bearing body and the arc length and the curvature at the corners of the side bearing body are rapidly measured by using the second outer contour measuring mechanism.

The invention relates to a variable-width volute spiral spring design method and a volute spiral spring, and belongs to the technical field of volute spiral springs.The variable-width volute spiral spring design method comprises the steps that S1, polar angles corresponding to plane spiral lines at different arc length positions are determined; s2, determining curvature radiuses corresponding to the planar spiral lines at different polar angle positions; s3, according to different curvature radius parts, the initial section width of the volute spiral spring is designed; and S4, the initial width of the volute spiral spring is adjusted according to the ratio of the radius to the half thickness of different parts, and uniform distribution of bending stress is achieved. The core of the method is that a corresponding width change rule is designed according to a change rule of bending stress along with curvature radius disclosed by a curved beam theory. By means of the method, the maximum bending stress of all the sections can be equal, and therefore the bearing capacity and stability of the volute spiral spring are improved.

The invention relates to the technical field of tire manufacturing, and discloses a low-rolling-resistance truck radial tire which comprises a tread, a sidewall, a belted layer, a tire body, a steel wire ring and steel wire wrapping cloth, the outer contour of the tread is of an arc-shaped structure on a tire interface, the arc length of the tread is L, the arc length L adopts the design of two sections of tangent arcs, and the arc length L is larger than the arc length L; the tread is provided with three pattern grooves which divide the tread into four same pattern blocks, the three pattern grooves are composed of two conventional open type longitudinal grooves and a Y-shaped longitudinal groove in the longitudinal direction, and the Y-shaped longitudinal groove is located between the two open type longitudinal grooves. According to the truck radial tire with the low rolling resistance, by optimizing the structural design, the pattern design and the formula design of the tire, the tire has the ultra-low rolling resistance performance, and meanwhile eccentric wear and different wear can be effectively reduced.

The invention discloses a return stroke section optimization method based on three-dimensional free bending forming, which comprises the following steps: S1, obtaining an eccentric distance U of a bending die at a transition section of a pipe according to a U-R relation, and obtaining a relation function of a variable motion speed delta of the bending die and the U; s2, the axial movement speed of the bending die corresponding to each time node is calculated, meanwhile, a correction coefficient e is introduced, and finite element simulation is conducted; and S3, comparing the simulation result with the target bending member, and if the error is not in the allowable range, changing the correction parameter e to continue simulation until the error reaches the allowable range. The invention further discloses a return stroke section optimization device based on three-dimensional free bending forming. The arc length of the return stroke section is reduced, the quality and precision of a formed part are improved, and more complex pipe fittings can be machined and formed.

The invention discloses a ship navigational speed segmented measurement method suitable for an arc-shaped navigable tunnel test, and relates to the technical field of engineering measurement, and the method comprises the following steps: dividing a navigable arc-shaped segment of a tunnel into a plurality of uniform measurement segments, and erecting a laser range finder at the front end of each measurement segment; presetting an acquisition sequence, and sequentially acquiring distance data measured by the laser range finder when the test ship sails based on the preset acquisition sequence; based on the distance data measured by the laser range finder, the arc length of the test ship passing along the channel center line at any time position point is obtained; and obtaining the ship navigational speed based on the ratio of the arc length to the test ship navigational time. Through segmented measurement, real-time data acquisition and navigational speed calculation based on the arc length, the ship navigational speed measurement method with high adaptability, high precision and high real-time performance is provided for an arc-shaped navigational tunnel test, the defects in arc-shaped navigation channel measurement in the prior art are overcome, and the method has remarkable practical application value.

This invention discloses a method for analyzing the meridional strain of air springs based on piecewise integration of elliptical arc length, belonging to the technical field of vehicle suspension systems or rubber elastic elements design. The method includes the following steps: approximating the arc segment from the top of the air spring generatrix to the outermost bulge point as the first quadrant of an ellipse, determining the major and minor semi-axes of the reference and inflation states; introducing normalized coordinates to establish a linear mapping of the abscissas of the two states, constructing an elliptical arc length infinitesimal element and transforming it to the same interval for integration; dividing the interval into even-numbered equal parts, using the complex Simpson method to obtain the arc length piecewise, calculating the ratio of the inflation arc length to the reference arc length as the elongation ratio, and taking the natural logarithm to obtain the true meridional strain of each segment of the generatrix; this invention can accurately describe the non-uniform deformation of each segment of the generatrix during air spring inflation, providing a basis for strain prediction and fatigue assessment.

A three-dimensional curved surface forming method comprises the steps that stretch-forming machine stretching cylinders arranged on the two sides of the mold stretch-forming direction of a three-dimensional curved surface forming tool and stretch-forming machine stretching cylinder clamps capable of rotating around a shaft in a segmented mode move together so that bending and stretching motion loads can be applied to the two ends of a plate laid on a mold, and therefore the plate can be attached to the mold in a segmented mode; the x-direction contour section line with the largest chord height of the mold serves as a control contour section line, then stretch-forming area segmentation division is conducted on the control contour section line according to the curvature and arc length changes of the control contour section line, dispersion of the elongation of each stretch-forming area is achieved, and finally stretching is conducted according to the stretch-forming elongation of each stretch-forming area, so that the stretch-forming area is obtained. And a three-dimensional curved surface with high appearance precision is further obtained. Segmented stretch forming is provided, the elasticity and plastic deformation uniformity in the stretch forming range of each section is effectively improved, deformation uniformity of overall stretch forming is achieved, and the stretch forming precision and the stretch forming efficiency of the stretch forming process are comprehensively improved by dividing the stretch forming areas.

A method for calculating the in-plane nonlinear deformation of an arch structure with axial defects in a Cartesian coordinate system is presented. This method is based on two states of the arch structure's curve element in the Cartesian coordinate system: an ideal axis and an actual axial defect. It derives the changes in the arc length and curvature of the curve element before and after deformation, obtaining expressions for the nonlinear compressive and bending strains in the in-plane of the arch structure with axial defects in the Cartesian coordinate system. The method also derives the nonlinear equilibrium differential equations in the in-plane of the arch structure with axial defects in the Cartesian coordinate system, obtaining solutions that satisfy the mechanical and geometric boundaries of the arch structure with axial defects. Finally, the method derives the nonlinear equilibrium governing equations in the in-plane of the arch structure with axial defects, ultimately obtaining the solution to the nonlinear mechanical problem in the in-plane of the arch structure with axial defects in the Cartesian coordinate system. This method can obtain the essence of the nonlinear mechanical problem of the arch structure with axial defects in the Cartesian coordinate system, filling the gap in the nonlinear strain-displacement expression for the in-plane of the arch structure with axial defects in the Cartesian coordinate system.

The application relates to the technical field of motion planning, and discloses a corner fairing method of an asymmetric Airthoid-arc, which comprises the following steps: constructing a tool path fairing curve which is sequentially connected by a first Airthoid curve, an arc and a second Airthoid curve, and is used for fairing a corner formed by adjacent straight line segments; preliminarily setting a first transition length and a second transition length according to the lengths of the line segments on the two sides of the corner; solving the first and second tangent angles according to geometric constraints, tangential continuity, curvature continuity constraints and position continuity constraints; if there is a solution, analytically calculating a current approximate error; and finally analytically calculating the curvature extreme value and the arc length of the fairing curve. The asymmetric curve structure is adopted, the corner space is fully excavated, the curvature extreme value is small, the arc length can be analytically expressed, and the profile error is controllable, so that the numerical control machining efficiency is improved.

The application relates to a three-dimensional continuous shape estimation method and system of a flexible robot, wherein the method combines the arc length of the flexible robot and unknown external loads from the environment with a Cosserat elastic rod model and a Cosserat elastic string model to generate a Lie algebra coupled statics model representing a tendon-driven model, models the external loads as Gaussian process noise to construct a prior probability model, obtains a prior probability distribution of the flexible robot in a Lie algebra space, constructs a measurement noise model in the Lie algebra space according to discrete measurement poses captured by a sensor and measurement noise, obtains a predicted measurement value, fuses the prior probability distribution and the predicted measurement value to obtain a posterior shape estimation of the flexible robot, and calculates a continuous three-dimensional shape estimation of the flexible robot and a first credibility of the continuous three-dimensional shape estimation according to the posterior shape estimation and a Gaussian process interpolation method. Therefore, the application realizes accurate perception of the continuous three-dimensional shape of the flexible robot.

The utility model relates to the technical field of high-altitude platforms, and discloses an arc convolution platform attached to a high-altitude bridge. The keel frame is fixedly connected to the side, provided with the arc-shaped plate, of the horizontal plate, the keel frame comprises a variable-curvature sector ring frame, the variable-curvature sector ring frame comprises an outer arc edge, an inner arc edge and two ring wide edges, the inner arc edge is attached to the outer edge of the arc-shaped plate, and the curvature and the arc length of the outer arc edge are larger than those of the inner arc edge; the tempered glass plate is fixedly installed on the keel frame and comprises an outer arc edge, an inner arc edge and two annular wide edges, the inner arc edge is attached to the inner arc edge, the annular wide edges are longer than the annular wide edges, the curvature of the outer arc edge is the same as that of the outer arc edge, and the arc length of the outer arc edge is larger than that of the outer arc edge; the technical problem that an existing sightseeing platform cannot be used for stage performance and cannot meet the suspension effect is solved.

This utility model relates to the field of vehicle gas supply technology and discloses a gas cylinder mounting bracket, including a first main body and a second main body fixedly connected. The front of the first main body has an arc-shaped portion along its length, and a straight portion extends smoothly from the end of the arc-shaped portion. The shape of the arc-shaped portion is adapted to the gas cylinder, and the arc length of the arc-shaped portion satisfies the following condition: the plane where the end of the arc-shaped portion and the straight portion are located is above the plane where the lowest point of the arc-shaped portion is located and below the plane where the beginning of the arc-shaped portion is located. A first groove is provided on the back of the first main body along its length to fit the second main body into the first main body, and both ends of the second main body extend beyond the corresponding ends of the first main body. A protrusion is provided at the end of the second main body, protruding towards the front of the second main body and inclined at the top. Reinforcing members are provided at both ends of the second main body. Mounting holes are provided at least at the beginning of the second main body and the protrusion. Mounting members are provided on both sides of the first main body. This bracket meets the ground clearance requirements of existing vehicles, changes and simplifies the assembly process, optimizes overall strength, and provides high gas cylinder protection performance.

The invention relates to the technical field of structural design optimization, in particular to a structural parameter optimization design method and system based on sheet metal parts. The method comprises the following steps of calculating a normal included angle field by extracting a surface patch normal and a surface center coordinate of a CAD model, identifying a rib position transition area, and performing arc length calculation, curvature point analysis, step jump judgment and transition curve fitting based on a rib rotation angle coefficient. And the fatigue performance and the structural design optimization effect of the fitted curve are verified through a load cycle test. According to the method, the transition rib position area of the sheet metal part is accurately recognized through the normal included angle field, fine parameterization of the curve form is achieved in combination with the rib rotation angle coefficient, then step jump analysis and fitting are carried out, the stress streamline and structure transition design is optimized, the improvement effect of the method on the fatigue performance is verified through a load cycle test, and therefore the damage risk is effectively reduced, and the fatigue performance of the sheet metal part is improved. And the service life and reliability of the sheet metal part under the repeated load are improved.

The invention discloses a high-precision laser cutting tool and cutting method for a variable-cross-section semi-cylindrical sheet metal part, relates to the technical field of laser cutting, and solves the problem of cutting precision deviation of such parts. The tool designed by the invention comprises the reference plane used for drawing the arc length contour line of the part in the early stage and detecting the arc length size of the part, the whole tool is formed by splicing and welding a plurality of common steel plates, and the upper molded surface of each vertical plate is consistent with the outer surface of the part in shape, so that the effective fitting and supporting effects on the part are ensured; and the other steel plates have fixing and reinforcing effects. The cutting method comprises the steps that allowance is reserved for lineation on a sheet metal part, cutting is conducted after red light emitted by the laser device is manually adjusted and aligned with the lineation, after cutting is completed, the deviation between the actual cutting size and the expected cutting size is calculated through measurement, and then correction is conducted by adjusting the ordinate value in the cutting program. And finally, precise cutting of the variable-cross-section semi-cylindrical sheet metal part is achieved, and the high-precision size requirement of the part is met.

An example embodiment includes: obtaining a specification of a target deformation shape for a substance, wherein the substance has a plurality of material control points with respective curvatures and arc lengths defining the target deformation shape, and wherein the substance includes thermo-active components and non-thermo-active components; determining a set of relations between indications of presence of the thermo-active components or the non-thermo-active components, orientations of the thermo-active components, and deformation capabilities of the thermo-active components; providing, to an optimization solver application, the specification, the set of relations, and instructions to determine values of the presence of the thermo-active components or the non-thermo-active components within the locations of the target deformation shape and the orientations of the thermo-active components, such that the substance can attain the target deformation shape in response to a temperature change when in a non-deformed state; and receiving, from the optimization solver application, the values as determined.

A manufacturing method of a titanium alloy front engine case forging, comprising designing the outer shape structure of a pre-forging blank according to the arc length of the forging; compensating the arc length value by thickening the height size of the corresponding part on the profile surface of the pre-forging blank corresponding to the outer circle of the forging; adding two trapezoidal bosses on the profile surface of the pre-forging blank corresponding to the inner circle of the forging, the positions being the two sides in the length direction; adding a boss in the middle area of the profile surface of the pre-forging blank corresponding to the outer circle of the forging; adding a boss on the profile surface of the pre-forging blank corresponding to the inner circle of the forging, which is used for positioning when the pre-forging blank is put into the die for pre-forging. The present application overcomes the shortcomings of the prior art, can effectively optimize the excess amount distribution of the forging and refine the size of the forging, thereby effectively improving the material utilization rate and effectively improving the product quality. And the lean control of the manufacturing process is strengthened, the material utilization rate is improved. The production process is simplified, and the manufacturing cycle is shortened.

On the one hand, the present application provides a method for modeling a leading-edge damaged blade, including: extracting the airfoil coordinates of different blade height cross-sections, and calculating the mean camber line and thickness distribution of each airfoil; for the airfoil with a leading-edge curling damage, taking point A as the starting point and point P as the center to make an arc with an arc length of s, and superimposing the corresponding thickness distribution on the arc to obtain the airfoil suffering from curling damage, where point A is the termination position of the curl on the mean camber line, PA = s / (2θ), and PA is perpendicular to the outer tangent AQ of point A on the mean camber line, s is the length from point A on the mean camber line to the leading-edge point L, and θ is the curling angle; stacking each airfoil of the blade along the blade height direction to obtain a three-dimensional model of the leading-edge damaged blade. On the other hand, a method for simulating the aerodynamic characteristics of a full-ring fan blade is provided, and this simulation method is implemented based on the above-mentioned method for modeling a leading-edge damaged blade.

The utility model provides a hook assembly for gear hanging and conveying, and belongs to the technical field of machinery. The problem that an existing conveying structure is inconvenient to adapt to different gears is solved. The hook assembly for gear suspension conveying comprises a hook and a strip-shaped support, rolling wheels are installed at the two ends of the support, a vertically-arranged rod body is arranged at the upper end of the hook, the support is made of elastic materials, a round rod is vertically formed on the top face of the rod body, and the outer diameter of the round rod is smaller than that of the rod body; a round hole allowing the upper end of the round rod to penetrate through is vertically formed in the support in a penetrating mode, and the outer circumferential face of the round rod is attached to the inner circumferential face of the round hole. One side of the circular hole is vertically provided with an opening, and the ratio of the arc length of the inner circumferential surface of the circular hole to the arc length of the whole circle is greater than 3 / 4; a baffle ring is formed on the outer wall of the upper end of the round rod and pressed on the top face of the support, and the outer diameter of the baffle ring is larger than the diameter of the round hole but smaller than or equal to the outer diameter of the rod body. The support is further provided with a connecting structure which enables the support and the round rod to be detachably and fixedly connected. The hook assembly for hanging and conveying the gears is convenient to adapt to different gears.