56 results about "Buckling instability" patented technology

The invention relates to the technical field of hull beam ultimate bearing capacity prediction, in particular to an axial pressure stiffened plate ultimate strength prediction method, which comprisesfour stages including a linear deformation stage, a buckling instability stage, a nonlinear large deformation stage and a failure stage in the deformation process of an axial pressure stiffened plate,for the four stages, respectively calculating a similarity criterion corresponding to each stage; constructing a model of the stiffened plate according to the parameters of the prototype of the stiffened plate to be predicted and the similarity criterion of the four stages; and predicting the ultimate strength of the prototype according to the model. According to the method, the stiffened plate can be predicted according to the whole deformation process of the stiffened plate under the axial compression condition, so that the similarity prediction precision is improved.

The invention discloses a buckling micro-force sensor and a micro-force measuring method based on twin beams or serial connection twin beams, and belongs to the fields of micro-nanomechanics and precise measurement. A group of symmetrical slim beams or two groups of serial connection slim beams are adopted in the sensor, the slim beams are arranged in a parallel mode, one end of each slim beam is fixed, the deformation of the slim beams is limited through limiting ends, a load is applied through a probe and a capacitor, and the displacement is measured. In the process of using, the twin beams are bent to be instable in the axis in advance, and the buckling mode of the twin beams is kept. By appropriately leading in the transverse displacement of the twin beams, the obvious transverse displacement change of the twin beams can be obtained under the very small axial force within a certain load range, and the value of the measured micro-force is obtained through load calculation based on the buckling instability formula or directly obtained through the changes of the displacement via the early calibration. The buckling micro-force sensor is simple in structure and in sensitivity, sequence sensors in different measuring ranges can be formed, and therefore the micro-force measuring method and the sensor design both of which have a wide range of loads and high sensitivity can be provided for the measurement of the micro-nanomechanics.

The invention provides a preparation method of a super-sliding block. According to the preparation method, buckling instability and structural damage of the super-sliding block are avoided by improving a loading mode. The method comprises the following steps: etching a platform at the tip of a probe by using a focused ion beam etching method and the like, contacting the platform with a super-slideblock, changing a loading mode into a mode of contacting the super-slide block from the top by using the probe, and applying positive pressure and shearing force so as to push the slide block. The method provided by the invention is simple and convenient, and can avoid the problem that the slide block is damaged due to buckling instability under the pushing of the probe when the super-slide blockis large. Meanwhile, the method provided by the invention can improve the yield of batch production of the ultra-sliding blocks, and has wide applicability.

The invention discloses a multi-girder structure large size wind power blade and a production method thereof. The multi-girder structure large size wind power blade is in a hollow layout structure, and comprises a blade envelope suction edge, a blade envelope pressure edge, main load-carrying construction girders and shearing-resistant web plates, wherein the blade envelope suction edge and the blade envelope pressure edge are combined to form a cavity structure of which the cross section is streamlined; a supporting structure formed by the main load-carrying construction girders and the shearing-resistant web plates is arranged in the cavity structure formed by the blade envelope suction edge and the blade envelope pressure edge; and the blade envelope suction edge and blade envelope pressure edge are in multisection combination structures, and are connected with the side surfaces of the main load-carrying construction girders through a plurality of edge sections respectively to form a blade envelope suction edge and blade envelope pressure edge integrated body. On the premise of ensuring the rigidity and strength of the blade, the resistance to buckling instability of the blade is improved; and by adopting a high-module carbon fiber spread layer, the weight of the blade can be reduced obviously, and loads, particularly a fatigue load, of the blade are reduced.

A vacuum chamber with an innovative wall structure. Instead of a conventional homogenous wall structure, the invention uses an array of internally-pressurized, thin-walled cells to contain an enclosed volume. The walls are arranged so that when a vacuum is present in the enclosed volume, the cell walls are placed primarily in tension. In this way the likelihood of buckling instability is substantially reduced. The result is a much lighter vessel compared to a conventional homogenous wall vessel of similar strength.

The invention discloses a creep age forming method for a large thin-wall component. The method comprises the following steps that firstly, an aluminum alloy blank is cut into a component plate containing a component unfolding body; a metal plate is cut into an auxiliary plate with an outer contour consistent with an outer contour of the component plate; the component plate and the auxiliary plateare tightly attached and fixed to form a reinforcing plate; the reinforcing plate is placed on a mold face, and the reinforcing plate is completely coated with ventilated felt; a sealant is pasted onthe edge portion of a mold, and a vacuum bag is pasted on the sealant so as to make the vacuum bag and the mold jointly form a closed space; the closed space is vacuumized to make the reinforcing plate be close to or keep attached to the mold face; the reinforcing plate and the mold are put into an autoclave for vacuum creep age forming, and after completion, the component plate, the auxiliary plate and the mold are separated; and an allowance plate is milled. According to the method, precise shape and property integrated forming of the large thin-wall component can be achieved, and a local buckling instability condition of the component with the weak rigidity in the creep age forming process is effectively restrained.

The invention discloses a forging forming die for a cylindrical part plate with a small fillet characteristic. The forging forming die comprises an inner side male die, an outer side male die, a female die, a female die base plate and a floating mandrel. The invention further provides a forging forming method for the cylindrical part plate with the small fillet characteristic. A pipe blank with the outer diameter equal to that of a cylindrical target part is put on the female die base plate, and the inner side male die and the outer side male die are driven to synchronously move downwards at aconstant speed to upset and extrude the pipe blank to form an inner flange upsetting piece. After moving to the lower limit, the outer side male die is kept still with constant load, the inner side male die continues to descend to shear the inner flange upsetting part, a metal material is forced to continuously flow to a closed cavity defined by the inner side male die, the outer side male die, the female die, the female die base plate and the floating mandrel, and finally the cylindrical part with the small fillet characteristic is upset and extruded. The cylindrical part with the small fillet characteristic is formed in one procedure, the buckling instability problem is solved, the defects of folding, inward sinking and the like are overcome, and the fillet filling plumpness and the mechanical property of the target part are improved.

The invention provides a power transmission tower reinforcing device capable of preventing bending and buckling instability, and belongs to the technical field of iron tower reinforcement. The power transmission tower reinforcing device comprises reinforcing channel steel, a reinforcing steel column, two pieces of reinforcing T-shaped steel and a reinforcing outer connecting plate, wherein the reinforcing outer connecting plate is fixedly connected with two free ends of the reinforcing channel steel separately; the reinforcing outer connecting plate and the reinforcing channel steel are enclosed to form a rectangular cavity for accommodating the reinforcing steel column and the two pieces of reinforcing T-shaped steel; the two pieces of reinforcing T-shaped steel and the reinforcing channel steel are enclosed to form a triangular cavity for accommodating power transmission tower angle steel; and the reinforcing steel column and the reinforcing T-shaped steel are separately positioned at the inner side and the outer side of two limbs of the power transmission tower angle steel. According to the power transmission tower reinforcing device capable of preventing bending and buckling instability provided by the invention, the two pieces of reinforcing T-shaped steel and the reinforcing outer connecting plate are arranged at the outer side of the power transmission tower angle steel, and the reinforcing steel column and the reinforcing channel steel are arranged at the inner side of the power transmission tower angle steel, so that the power transmission tower reinforcing device has a prominent bending and buckling preventing effect, has enough stability, is simple in structure, is simple and convenient to mount, and is low in cost.

A method of simulating the movement of cloth and a computer-readable medium storing a program which executes the method of simulating the movement of cloth, wherein cloth deformation by compressive force is simulated by an immediate buckling model when the compressive force is applied to two extremities of a deformation unit which models the cloth, cloth deformation by stretching is simulated by a spring model, and hysteresis phenomenon of cloth is simulated by using spring-slips for modeling. The immediate buckling model is based on a model of the present invention in which a deformation unit is not contracted by compressive force and generates an immediate bending deformation. As for the compressive force and stretching, simulation is implemented by separate models, hysteresis phenomenon of cloth is simulated by use of spring-clips for modeling, whereby cloth characteristics can be well reflected and the buckling instability of cloth caused by compressive force can be solved, thereby increasing the simulation speed.