37 results about "Shape finding" patented technology

The invention discloses a power transmission line wind-induced response finite element analysis method coupled with a local wind field. The method mainly comprises two parts of finite element analysisand wind field simulation. The method comprises: firstly, obtaining peripheral elevation data of a power transmission line, establishing a calculation domain, performing grid division, and then calculating wind field values; then establishing a geometric model and a finite element model of the power transmission line, and performing initial shape finding calculation; and finally, dividing the power transmission tower into a plurality of tower sections, calculating a wind load according to the wind field value of each tower section in combination with the windward side projection area of the power transmission tower line and a wind load model, and carrying out finite element analysis after the power transmission tower line is loaded to obtain a wind-induced response result. According to the method, the finite element model of the power transmission line and the wind-induced response result under different wind field conditions are obtained, and the terrain model and the wind field value around the power transmission line are obtained. The method is suitable for analyzing the wind-induced response of the power transmission line under various topographic conditions, and fully reflects the influence of the local wind field characteristic condition on the power transmission line.

Embodiments of the invention provide a bridge structure design shape finding method and device, and the method comprises the steps: S1, building an initial structure model of a bridge, and carrying out the static structure analysis of the initial structure model; S2, based on a static structure analysis result, performing topological optimization on the initial structure model by taking the volumereduction amount as a constraint condition and taking the maximum rigidity as an objective function to obtain an optimized structure model; and S3, if it is known through judgment that the optimizedstructure model meets the optimization design target, taking the optimized structure model as the structure model of the bridge. According to the embodiment of the invention, topological optimizationis carried out on an initial structure model by taking the volume reduction amount as a constraint condition and taking the maximum rigidity as an objective function. Compared with an initial structure model obtained by a traditional bridge design method, the obtained optimized structure model has higher stress and lower mass, so that the material cost can be reduced, and greater economic benefitscan be obtained.

The invention discloses a side span shape finding method adopting resultant force control in a horizontal plane. The method comprises the following steps: taking a vertical component force of a side span main cable at a theoretical vertex as an iterative variable, taking a vertical coordinate of the theoretical vertex or an anchoring point at a splay saddle as an iterative target, adding a new control item, i.e., an included angle between a resultant force in a horizontal plane and a longitudinal axis of a side span end part, and carrying out loop iteration on a side span cable system until aprecision requirement is met. According to the side span shape finding method, it is guaranteed that the longitudinal component force and the transverse component force of the cable force on the towertop are equal, in other words, the resultant force in the horizontal plane is equal, the bridge tower can be completely vertical, the obtained side span line shape and the obtained middle span line shape do not have folded angles on the tower top, and the transverse coordinates of the theoretical vertex or the anchoring point of the splay saddle can be accurately calculated. When the bridge forming state of the space cable suspension bridge is determined, the side span shape finding method controlled by the resultant force in the horizontal plane is successfully applied to the design of a large canyon glass bridge with the main span of 430 m.

The invention relates to a contact line static space position-based contact network suspension three-dimensional rapid shape finding method. The method comprises the following steps: firstly, calculating vertical forces of a contact line dropper point and a positioning point according to a contact line static space position; calculating the three-dimensional static shapes of the carrier cable andthe elastic sling according to the static space position of the contact line, the vertical force of the dropper point and the displacement constraint of the dropper point of the contact line; calculating the gradient and the spatial position of the positioner according to the static spatial position of the contact line, the vertical force of the positioning point and the length of the positioner;and finally, calculating the three-dimensional static shape of the contact network suspension according to the three-dimensional static shapes of the carrier cable and the elastic sling at the staticspace position of the contact line and the slope of the positioner. According to the method, the actual stress state and elastic deformation of the overhead line system suspension cable are considered, the method is simple and efficient, simple chain shapes of various line conditions and actual contact line static space positions and three-dimensional static shapes of elastic chain shape suspension can be accurately calculated, and the method is directly applied to pantograph-catenary system design, overhead line system construction pre-configuration and overhead line system state maintenance.

The invention discloses a mesh-shaped extendible antenna shape-finding method based on triangular patch errors. The method includes the steps of deducing the conversion relation between rectangular coordinates and area coordinates on the basis of definition and property of the area coordinates, establishing a new cable and beam combination structure shape-finding optimizing model on the basis of a patch error numerical value integral calculating formula of the area coordinates with the minimized patch errors as the target function and the cable unit non-looseness as the constraint, and converting an optimization model into a standard secondary planning problem to be solved by means of a sequence secondary planning method. The shape surface precision of a reflection surface can be improved when it is ensured that a cable section is free of looseness, and meanwhile the mechanical property of an antenna structure is improved compared with a traditional shape-finding method; the precision of the reflection surface can be accurately represented, and the result is more reliable; meanwhile, the patch errors should be considered in the shape-finding process, and the shape-finding result better than that obtained with the minimized node root-mean-square error as the target can be obtained with the minimized reflection surface patch error as the target.

The invention provides a method for shape-finding and constructing of an air-rib-type ice shell building. The method comprises the steps: building data of the ice shell building are calculated, and aplurality of air rib arch basic units are manufactured through the obtained building data; the multiple air rib arch basic units are inflated for the first time, and the multiple air rib arch basic units inflated for the first time are connected in parallel to form an air rib arch set; the air rib arch set is subjected to foundation fixing, and after foundation fixing completed, the multiple air rib arch basic units in the air rib arch set are synchronously inflated for the second time; after second-time inflating is completed, an ice and snow composite material is sprayed on the outer surfaceof the air rib arch set to form an ice shell; and after the thickness of the ice shell reaches a preset value, the inflatable rib arch set is removed, and the ice shell building is manufactured. Themultiple air rib arch basic units can be synchronously inflated, and thus the manufacturing time of the ice shell building is shortened; and the air rib arch set formed by the multiple air rib arch basic units which are connected in parallel can be subjected to foundation fixing, and thus shape-finding of the air rib arch set is convenient.

The invention relates to a reticulated shell shape optimization method based on iterative shape finding, which comprises the following steps: 1) setting a reticulated shell initial structure, obtaining an initial node coordinate and an initial axial force, and setting an initial external load of the structure; 2) calculating a stiffness matrix of the current iteration stage according to the node coordinates and the axial force of the current iteration stage; 3) setting a boundary condition by adopting a zeroing setting method, and solving a node coordinate of a next iteration stage through anoverall balance equation according to the rigidity matrix, the node coordinate and the external load of the current iteration stage; 4) according to the node coordinates of the next iteration stage and the rigidity matrix of the previous iteration stage, calculating through a unit balance equation to obtain the axial force of the next iteration stage; and 5) setting a convergence condition, if theconvergence condition is satisfied, completing reticulated shell shape optimization, and otherwise, returning to the step 2) until the convergence condition is satisfied. Compared with the prior art,the reticulated shell shape optimization method has the advantages of simple steps, rapid convergence, convenient adjustment, suitability for single-layer and double-layer reticulated shells and thelike.

The invention belongs to the technical field of bridge engineering. The invention provides a suspension bridge space cable shape finding method based on finite elements. The suspension bridge space cable shape finding method comprises the following steps: 1) establishing an initial finite element model containing a main cable and a suspender, a lifting point of the lifting rod on the main beam only restrains longitudinal and vertical degrees of freedom, and releasing lateral constraints, applying a suspender transverse tensioning force design value, so as to ensure that the tension force of the suspender in each step of iterative calculation is always a design required value; 2) updating the finite element model after determining the line shape and the internal force initial value of the space cable by applying a small elastic modulus technology; (3) updating the cable line shape and the internal force through nested loop expansion iterative computation and internal loop, ensuring thatthe internal force of a convergence result suspender is a design requirement value, correcting a main cable node coordinate through external loop, ensuring that a convergence result main cable control point coordinate is a design value, performing internal and external loop alternate iteration until a convergence requirement is met, and (4) outputting a result. The suspension bridge space cable shape finding method is simple to operate, stable in convergence, high in precision, high in speed, high in universality and convenient for engineering application and popularization.

The invention discloses a cable membrane structure shape finding design method based on a particle swarm optimization algorithm, and the method comprises the following steps: selecting the particle swarm optimization algorithm as a basic method for the shape finding of a cable membrane structure through employing a numerical simulation method, determining the optimization steps and flow, and building a cable membrane structure optimization model. Three surfaces with different projection shapes, namely a rotary catenary surface, a saddle surface and a rhombic hyperboloid, are selected as examples, and a shape-finding analysis model of the cable membrane structure is established by a self-programming method; a shape finding form diagram and a membrane surface stress distribution diagram areobtained through shape finding optimization analysis, and a calculation result and an analysis value determined by the particle swarm algorithm for structure shape finding are further obtained, and thus further confirming a membrane initial prestress value with an optimal membrane surface shape finding result and obtaining an optimal cable membrane structure initial shape. And load analysis is performed on the cable membrane structure, and a judgment criterion of the cable membrane structure wrinkling is researched. Through wrinkle analysis on a typical cable membrane structure, the processingmethod for avoiding wrinkles is obtained. Therefore, the optimal shape finding of the cable membrane structure is achieved.

The invention relates to a jacking installation method for a large-span single-layer aluminum alloy circular reticulated shell, and belongs to the technical field of building construction. According to the construction method, a local ladder-step-shaped supporting frame is erected on the lower portion of a latticed shell, the latticed shell is assembled on the upper portion of a frame body, a hydraulic jacking machine is erected, the assembling method of lifting while expanding is adopted till the latticed shell is jacked to the in-place height, and finally shape finding and folding are conducted at the high altitude, stainless steel bolts at joints are finally screwed, positioning and seating are conducted, and graded synchronous unloading is conducted to complete latticed shell installation. According to the method, the purposes of low construction cost, high construction speed, advanced technology, safety, reliability and excellent quality are achieved, the method is applied to installation of the large-span single-layer aluminum alloy latticed shell for the first time in China, and the method is of great significance to improvement of engineering construction safety, guarantee of engineering quality and reduction of engineering cost and has good application and popularization value.

The invention discloses a shape finding method of a large-opening cable-supported lattice structure. The shape finding method has the advantages that the reasonable support on an upper rigid system by a lower tensioning cable rod system can be realized, the vertical state of a support rod of the tensioning cable rod system can be maintained, the height of the support rod is limited, the attractive building effect is reached when the stress is reasonable, and the shape finding result of the cable rod system can be further corrected, so the structure system can be suitable for various load work conditions, and the stress is more reasonable.

The invention discloses a wire non-contact real-time time sequence image frame vision measurement device and method. The device includes a transmission lines, a spacer, a camera mechanism, a data processing module and a wireless signal emission module; the spacer is fixedly arranged between the transmission lines and is used for limiting relative motion between the transmission lines; the camera mechanism is fixed on the spacer and is used for shooting a microspur video image; and the data processing module processes the microspur video image shot by the camera mechanism and sends a processing result to a ground monitoring center through the wireless signal emission module. The wire non-contact real-time time sequence image frame vision measurement device first performs real-time evaluation on the state of a wind load and calculates shape factors of the transmission lines and an included angle between the wind load and a wire direction, a calculation formula of the wind load is utilized to calculate the wind load, then modal analyses of the transmission lines are made, shape finding of the transmission lines under the action of the wind load and a gravity load, an image algorithm is utilized to obtain distribution of stress on a wire, finally, a comparison with a stress critical value is made, and an early warning mechanism is established.

The invention provides analysis of mechanical properties of warp-knitted wire mesh based on the finite element method. The method comprises following steps: 1) determining data point 3D coordinates according to a coil structure of a minimal repetitive structure of warp-knitted wire mesh; 2) determining 3D coordinates of data points of the whole warp-knitted wire mesh according to the topology relationship among the minimal repetitive structure; 3) using the 3D coordinates of the data points of the whole warp-knitted wire mesh as key point coordinates of finite element modeling to build finite element models; 4) applying contact constraint based on the finite element models of the whole warp-knitted wire mesh; 5) applying loads and boundary constraint on the whole warp-knitted wire mesh to realize statics analysis. The invention realizes mechanical analysis of warp-knitted wire mesh based on finite element method and provides theoretical basis for the development of wire mesh and provides reference for the shape-finding analysis of cable net and screen laying process in the future.

The invention discloses a curved wood component cutting system and method, and aims to solve the problems of serious material waste, low processing efficiency and limited processing range in the priorart. The cutting system comprises a computer, a control system, a cutting device and a driving mechanism used for driving the cutting device; the computer comprises a modeling unit, a shape finding unit, a path planning unit and a programming unit; through the modeling unit and the shape finding unit of the computer, the minimum-volume initial component material wrapping a target curve componentis directly found, a cutting program is output through the path planning unit and the programming unit, the cutting device is controlled to conduct cutting according to a cutting path, so that material waste is avoided, and the cutting accuracy and the cutting efficiency are improved; the cutting device is driven by the driving mechanism to move, so that the spatial motion freedom degree is improved, accordingly, more complex components can be machined, the machining range is enlarged, and the cutting device is suitable for rapid cutting forming of single-curve and double-curve components.

A method for shape-finding optimization design of a strong-coupling tree structure includes such steps of setting initial parameters, establishing a tree structure with two-element numerical model; ifm is an odd number, applying the reverse load; solving the internal force of each branch and calculating the temperature load of all branches; if m is an even number, applying a temperature load; extracting vertical displacement of all nodes; changing the node position according to the vertical displacement of the extraction point until the maximum node displacement is less than the threshold value, and finishing the shape-finding process. The method of the invention adopts the two-element numerical model, wherein the cross-sectional area of the rod element is far larger than that of the beamelement, and the beam element is provided with a very small bending rigidity, so as to overcome the problem that the tree-like model of the two-element cannot be solved because the rigidity matrix isnot satisfied with the rank. The method of the invention has very high precision and high efficiency, avoids heavy programming work, couples optimization and shape-finding in one iterative program, converges quickly, and ensures maximum stable bearing capacity of tree structure as a whole.

According to a joint iterative algorithm-based tree structure shape finding optimization design method, all components of a tree structure only receive the action of axis pressure under the action of a vertical load, and the problem that the stable bearing capacity of the components needs to be considered besides shape finding is solved. According to the method, the balance matrix is used for carrying out shape finding analysis on the tree-shaped structure, and on the basis, the Euler stable bearing capacity is introduced to consider the influence of the geometric length of the component on the stable bearing capacity. On the basis of carrying out shape finding on a tree-shaped structure by utilizing a balance matrix, a corresponding iterative algorithm is provided by combining with Euler stable bearing capacity of branches. A stiffness matrix is formed in general finite element software, and the internal force of the branches is extracted. The aim of optimizing the length of each branch is achieved by changing the force density of each branch. The reliability of the calculation method provided by the invention is verified through comparison with previous calculation results; and finally, through analysis of the large-scale space tree structure, the applicability of the algorithm to the large-scale tree structure is verified. The tree structure is optimized through the improved balance matrix method, so that the problem of calculation misconvergence caused by improper flexural rigidity of a double-unit method can be avoided. The research result of the method can provide a theoretical basis for the shape-finding optimization design of the tree structure.

The invention discloses a design method of a large-curvature cable-membrane structure, and aims to solve the technical problems that the existing cable-membrane structure is easy to generate larger deformation to change the shape size or loosen, and the analysis and design theory of the cable-membrane structure at home and abroad is not completely mature. The design method comprises the following steps: (1) carrying out performance analysis on a membrane material to be used by the large-curvature cable membrane structure; (2) adopting ANSYS software to carry out shape finding analysis on the large-curvature cable membrane structure; (3) selecting a membrane material with a proper thickness; (4) optimizing a reinforcing cable net in the large-curvature cable membrane structure; (5) carrying out technical verification and hardware optimization on the large-curvature cable membrane structure; and (6) designing proper light transmittance of the membrane material. According to the design method, a collaborative stress system of the steel cable, the membrane material, the hardware and the cable membrane support steel structure is optimized, the overall stress stability of the structure and the applicability of the component are improved on the premise that the material performance is brought into full play, and the building body art is perfectly expressed.

The invention discloses a transformer substation downlead space shape finding method, which comprises the following steps of firstly, respectively moving two hanging points of a downlead to the hanging positions, keeping the hanging points oriented according to design requirements, and then measuring the pull force of the hanging points along the orientation direction and the orientation angle relative to the horizontal plane; measuring the horizontal span L and the vertical height difference H between the two hanging points; and finally, establishing a corresponding relation between the horizontal span x and the vertical height y of each point on the downlead, calculating to obtain the multi-point data, and fitting according to the multi-point data to obtain the distribution attitude of the downlead in the space. The method has the beneficial effects that the line shape closer to the real condition can be obtained, the method is of great significance for predicting and evaluating thespatial distribution state of the downlead, a simulation result which tends to be real is provided for subsequent analysis and research, and the analysis accuracy is improved.

The invention provides an equal force density method-based shape finding method for a cable section of a geodesic line between two points of a curved surface. The method comprises the main steps of giving a curved surface equation, cable section initial point coordinate values and an inter-initial point discrete node number; equally dividing a horizontal projection straight line between two initial points to obtain discrete node coordinates of the cable section on the curved surface; establishing a force balance equation set of all cable section nodes; calculating out new node coordinates; and judging whether a difference value of two node coordinates meets a convergence condition or not, and if the condition is met, outputting all node information of the cable section of the geodesic line, or otherwise, returning to iteratively solve coordinate values of the cable section nodes. According to the shape finding method, the shape finding of the cable section of the geodesic line between the two points of the curved surface is realized by utilizing an equal force density algorithm, and the node information of the cable section of the geodesic line between the two points is obtained, so that a complex geodesic line cable net structure of the curved surface can be designed.

The invention discloses an overhead conductor shape finding method based on ABAQUS finite element software, and the method comprises the following steps: S1, calculating the length and elongation of aconductor under the action of gravity, and solving the length of the conductor under an unstressed condition, namely, the original length of the conductor; S2, calculating the linear distance of a wire hanging point, and comparing the linear distance of the wire hanging point with the original length of the wire calculated in the step S1 so as to judge the initial shape of the wire; S3, modelingis carried out according to the initial shape of the wire, initial assembly stress is preset, finite element analysis is carried out after the attenuation coefficient in the analysis step is set, a resolving result is obtained, and simulated sag and simulated maximum stress are obtained; And S4, calculating a relative error value of a resolving result, judging the correctness of modeling, finishing resolving if the error value conforms to a preset threshold condition, and returning to S3 to correct the attenuation coefficient in the analysis step and continuously executing until the error value conforms to the preset threshold condition if the error value does not conform to the preset threshold condition. The method is simple to operate, stable in calculation result and high in accuracy.

The invention discloses a novel degradable plastic packaging film, which comprises a packaging film and a cylindrical through hole inside the packaging film, and a connecting rod is set in the through hole, and the connecting rod includes a connecting rod, a connecting rod connected with the connecting rod A support rod, the support rod is covered with a fixed sleeve, the fixed sleeve is connected with four telescopic telescopic rods, the support rod is connected with a horizontal rotatable rotating rod, and the rotating rod is connected with A vertical vertical rod located outside the packaging film, the vertical rod is telescopic, and the vertical rod is connected with a parallel rod parallel to the packaging film, and the parallel rod is connected with a connecting rod A and a connecting rod B, The connecting rod B is connected with a search column with a pointed end, and the connecting rod A is connected with a driving column for driving the sticky side of the packaging film to be pulled out; control buttons.

The invention provides a design method of a parabolic-cylindrical-surface mesh deployable antenna based on a modular splicing thought. The design method comprises the main steps that 1, structural parameters of a parabolic-cylindrical-surface antenna back frame are given; 2, the total module number in the parabola direction of the antenna back frame is calculated; 3, the total module number in the base line direction of the antenna back frame is calculated; 4, the rib numbers in the parabola direction and base line direction of the antenna back frame are given, and a final back frame configuration is determined; 5, according to principle errors of an antenna reflection surface, the section number in the parabola direction of a network cable is calculated, and thus an ideal geometrical configuration of the network cable is generated; 6, shape design of the network cable is achieved; 7, a finite element model of a network cable-back frame structure is established, combined shape finding is conducted on the model, so that the shape and surface precision of the antenna meet the design requirement. The design method is based on the modular splicing thought, the deployable back frame of the parabolic-cylindrical-surface antenna is spliced by adopting a few varieties of modules, shape design of the network cable structure of the antenna is achieved, and the design scheme of a whole antenna structure is obtained.

The invention relates to a finite element shape finding analysis method for a cable structure, and the method comprises the following steps: building a broken-line-shaped finite element model of a cable structure, applying a concentrated load to a broken point of the finite element model, and solving an initial balance state solution of the cable structure under prestress and the concentrated load; under the initial balance state solution, continuously superposing the dead weight and / or the external load, and solving a working state solution obtained after superposing the dead weight and / or the external load on the cable structure; and eliminating the concentrated load, solving a final state solution, and determining the cable structure form. According to the method, broken line modeling is adopted, the modeling of the cable structure can be more convenient, and the initial balance state solution under the action of the concentrated load is obtained based on the finite element model ofthe broken line, so that the initial balance state solution of the cable structure can be more efficiently, simply and conveniently solved, the initial balance solution obtained through solving is transited to the working state solution, and the structural deformation under the dead weight and / or the external load can be more conveniently calculated.

The invention relates to a contact line static space position-based contact network suspension three-dimensional rapid shape finding method. The method comprises the following steps: firstly, calculating vertical forces of a contact line dropper point and a positioning point according to a contact line static space position; calculating the three-dimensional static shapes of the carrier cable andthe elastic sling according to the static space position of the contact line, the vertical force of the dropper point and the displacement constraint of the dropper point of the contact line; calculating the gradient and the spatial position of the positioner according to the static spatial position of the contact line, the vertical force of the positioning point and the length of the positioner;and finally, calculating the three-dimensional static shape of the contact network suspension according to the three-dimensional static shapes of the carrier cable and the elastic sling at the staticspace position of the contact line and the slope of the positioner. According to the method, the actual stress state and elastic deformation of the overhead line system suspension cable are considered, the method is simple and efficient, simple chain shapes of various line conditions and actual contact line static space positions and three-dimensional static shapes of elastic chain shape suspension can be accurately calculated, and the method is directly applied to pantograph-catenary system design, overhead line system construction pre-configuration and overhead line system state maintenance.

The invention discloses an initial shape-finding analysis method and system for icing stress of a power transmission line. The method comprises: equally dividing a wire into a plurality of wire unit sections in the horizontal direction in the whole span; determining an initial displacement vector of each conductor unit node through a catenary equation; and according to the elastic modulus, calculating and obtaining the initial original length and the elastic rigidity of each conductor unit section. The initial original length and the elastic rigidity of each conductor unit section can be quickly determined, initial calculation data are provided for iterative calculation when a finite element method is combined with a kinetic equation to analyze the icing stress of the power transmission line, and the pertinence and the calculation precision of icing stress analysis of the power transmission line are improved.

The invention provides a trampoline jumping cloth shape-finding method based on finite element analysis. The method includes following steps: modeling jumping cloth through APDL; defining material attributes of the jumping cloth, and valuing initial elastic modulus for the jumping cloth; performing grid division on a jumping cloth model by adopting a mode of mapping division through triangular units; utilizing displacement constraint to lift a central point of the jumping cloth by 0.4M; fully constraining surrounding displacement of the jumping cloth, and fixing all lines on the outer side ofthe round jumping cloth; applying temperature load on the round face of the jumping cloth to simulate prestress; updating coordinates of the jumping cloth: updating origin coordinates to coordinates after the temperature load is applied; restoring actual elastic modulus of a material; utilizing loop statement to execute steps (5), (6) and (7), wherein loop iteration is performed for 20 times in total; finishing shape-finding, applying actual working condition load, and solving. By the method, workload of shape-finding analysis can be lowered effectively, and accuracy of geometric shape of thejumping cloth in an initial state can be improved.

The invention discloses a power transmission wire shape finding method, system and device. The method comprises the following steps of: obtaining power transmission line information of a wire and determining a wire type; based on the line information and the wire type, establishing a form-finding transcendental equation set and a constraint equation set according to a force balance condition at aspacer; solving the transcendental equation set and the constraint equation set to obtain a spacer height difference, segmenting the conductor based on the spacer height difference, and calculating conductor sag and stress distribution in the conductor segment by adopting a catenary method; and determining the shape of the wire according to the spacer height difference, the wire sag and the stressdistribution. According to the method, the problem of inaccurate shape finding result caused by the fact that the prestress-free initial state information is difficult to obtain in an existing finiteelement method is solved. The method can be used for power transmission wire shape finding under complex conditions such as strain insulator strings, spacers and concentrated loads, and is wide in application range.