15 results about "Double cantilever beam" patented technology

The invention discloses a double-cantilever-beam piezoelectric vibration energy collector based on an annular steady state, which comprises a piezoelectric transducer, an elastic cantilever beam, a magnet and a base, after the piezoelectric transducer is mounted on the elastic cantilever beam to form a double-layer composite cantilever beam, the magnet is mounted at the free end of the double-layer composite cantilever beam, nonlinear coupling is carried out through repulsive magnetic force, and the piezoelectric transducer is connected with the base. The two-dimensional annular potential well structure with the adjustable potential well is formed, and the energy collector can easily trigger large-amplitude inter-well movement through the potential well structure. Through the nonlinear coupling induced internal resonance effect, inter-well energy transfer and two-dimensional potential well modulation are realized, and vibration energy can be efficiently captured in a broadband without a large amount of energy input or a complex structure. According to the design, the collection efficiency of low-frequency, low-intensity and multi-direction environment vibration energy in a wide working bandwidth is good.

The invention relates to the technical field of test equipment, in particular to a composite material DCB test clamp capable of measuring crack length, which comprises a lower T-shaped base and an upper T-shaped base, the upper T-shaped base is arranged at the upper end of the lower T-shaped base, a clamping mechanism is arranged on the lower T-shaped base, a lower supporting plate is arranged in the clamping mechanism, a fixing plate is arranged on the lower supporting plate, and a clamping mechanism is arranged on the fixing plate. A first fixing bolt is arranged on the fixing plate, a lower T-shaped connecting piece is arranged on the fixing plate, a lower T-shaped fixing piece is arranged on the lower T-shaped connecting piece, second fixing bolts are arranged on the two sides of the lower T-shaped fixing piece, a test clamping block is arranged at the upper end of the lower T-shaped fixing piece, a pin shaft is arranged on the test clamping block, a test mechanism is arranged on the upper T-shaped base, and an upper supporting plate is arranged in the test mechanism. A grating ruler connecting base is arranged on one side of the upper supporting plate, a third fixing bolt is arranged on the grating ruler connecting base, a grating ruler cross beam is arranged on the grating ruler connecting base, and the double-cantilever beam test piece can be clamped and limited according to needs by adopting the clamping mechanism.

The invention provides a differential photoacoustic gas sensing system and method based on cross-correlation demodulation, and is suitable for the fields of trace gas monitoring, industrial process fine control and environment detection. The system comprises a gas excitation light source, a symmetrical double-probe gas sensor, an optical fiber circulator, a wide-spectrum light source, a 1 * 2 optical fiber coupler, two pieces of plain glass, a photoelectric detection array and a computer, acoustic wave signals excited by the photoacoustic effect generate difference superposition cavity length changes on the symmetrically-arranged double cantilever beams, and environment noise triggers cavity length responses which are counteracted in the same direction. The system adopts an optical cross-correlation demodulation algorithm to track peak displacement of a cross-correlation function in real time, dynamically demodulates cavity length change information, and inverts the gas concentration according to the information. According to the design scheme, effective photoacoustic signals are remarkably enhanced, meanwhile, effective suppression of environment vibration noise is achieved, and finally the trace gas detection system integrating the advantages of miniaturization, high sensitivity and low cost is constructed.

The application relates to the technical field of material performance testing, and particularly relates to a heterogeneous material fracture toughness testing method, a double cantilever beam sample and a manufacturing method. The heterogeneous material fracture toughness testing method comprises the following steps: a double cantilever beam sample is provided, the double cantilever beam sample comprises a base layer, a first substrate and a separation layer, the first substrate is provided with the base layer on both sides in a first direction, the separation layer is arranged between the first substrate and any base layer, a separation area and a to-be-tested area are formed between the first substrate and the base layer adjacent to the separation layer in a second direction, and the separation area has a prefabricated crack; a sample testing step is performed, the double cantilever beam sample is installed on a testing device, the double cantilever beam sample is loaded by the testing device to make the to-be-tested area delaminate, and target data is acquired; and a result calculation step is performed, and a type I interlaminar fracture toughness value is acquired according to the target data. The heterogeneous material fracture toughness testing method provided by the application can improve testing accuracy.

The invention relates to the technical field of material performance testing, in particular to a heterogeneous material fracture toughness testing method, a double-cantilever beam sample and a manufacturing method. The heterogeneous material fracture toughness testing method comprises the steps that a double-cantilever-beam sample is provided, the double-cantilever-beam sample comprises base body layers, a first base plate and isolation layers, the base body layers are arranged on the two sides of the first base plate in the first direction, the isolation layer is arranged between the first base plate and any base body layer, and the isolation layers are arranged on the two sides of the first base plate in the first direction; an isolation region and a to-be-tested region are formed between the first substrate and the matrix layer adjacent to the isolation layer in the second direction, and the isolation region has a prefabricated crack; a sample testing step: mounting the double-cantilever beam sample on a testing device, loading the double-cantilever beam sample through the testing device so as to layer the to-be-tested area, and obtaining target data; and a result calculation step: obtaining an I-type interlayer fracture toughness value according to the target data. The heterogeneous material fracture toughness testing method provided by the invention can improve the testing accuracy.

The application discloses a wave-shaped twice-suspended beam structure and a construction method, and the twice-suspended beam structure comprises a main force-bearing suspended beam, an internal continuous suspended beam, an internal suspended beam tie rod and a support column; the main force-bearing suspended beam and the internal continuous suspended beam are both in the shape of a catenary; the main force-bearing suspended beams are fixedly connected through rigid nodes, the support column is connected with the rigid nodes of the main force-bearing suspended beams, the internal continuous suspended beam is fixedly connected with the main force-bearing suspended beam, and the internal suspended beam tie rod is hingedly connected with the internal continuous suspended beam; and a plurality of twice-suspended beam structures form a wave-shaped twice-suspended beam structure system. The twice-suspended beam structure is mathematically decomposed by using a catenary, the structural components have better buckling stability under the action of vertical loads and wind suction loads, the steel consumption of the structure system is low, the mechanical properties and economic performance are excellent, and the construction is convenient.

The application provides a kind of particle toughening composite interlaminar fracture toughness multiscale simulation and forward design method and system, belongs to the electric digital data processing technical field.The application is by constructing three-dimensional representative volume element (RVE) model containing random distribution spherical particle, and is endowed with its elastic-plastic constitutive and progressive damage model, combines periodic boundary condition, accurately characterizes mesoscopic toughening mechanism;Establish a macro double cantilever beam (DCB) model integrating mesoscopic characteristics, use extended finite element (XFEM) method to simulate crack initiation and propagation, realize the cross-scale forward prediction from mesoscopic parameters to macro I interlaminar fracture toughness.The application overcomes the problems of long development cycle, high cost of traditional trial-and-error method, and existing simulation model simplification distortion, scale disconnection, etc., can optimize the design by adjusting the particle size, volume fraction and other parameters, and provides a reliable theoretical tool and design system for interlaminar toughening design of high-performance composite materials.

The invention discloses an acid gas field conveying elbow cracking risk analysis method and system and a medium, and the method comprises the steps: obtaining the basic information of a certain block conveying elbow in combination with the actual working condition of an acid oil and gas field; constructing a finite element analysis model of a crack-containing elbow pipe structure according to the basic information of the conveyed elbow pipe; based on a finite element analysis model, equivalent stress fields and stress intensity factors of a crack-containing elbow structure under different parameter conditions are simulated and calculated, and then a stress intensity factor calculation formula of an elbow crack tip is determined in combination with a linear elastic fracture mechanics theory; a high-temperature and high-pressure kettle is adopted to simulate an acid gas field conveying pipeline field corrosion working condition environment, and a double-cantilever-beam method is adopted to measure the fracture toughness of a bent pipe structure material under the corrosion working condition environment; and based on the stress intensity factor calculation formula and the fracture toughness, carrying out conveying elbow cracking risk analysis. According to the method, the limitations that an existing evaluation method is not high in pertinence to the bent pipe structure, and the related calculation amount is large and complex are overcome.

The present invention discloses a method, device, medium, and product for reconstructing traction-separation curves, relating to the technical field of traction-separation curve analysis. This method employs a finite element model to iteratively update the crack opening within the cohesive region and calculates the energy release rate of delamination extension using the J-integral. Furthermore, a dual-cantilever beam theory formula is used to calculate the energy release rate at the crack front, establishing an equilibrium relationship based on the energy release rate based on the Dugdale condition. Finally, a gradient descent algorithm is employed to reconstruct the traction-separation curve. This method utilizes only DCB force-displacement data as input, eliminating the need for physical measurement of the crack opening displacement at the delamination tip. This significantly simplifies the measurement of the traction-separation curve, and the reconstructed traction-separation curve can accurately characterize damage mechanisms in complex situations.

The invention provides a multi-scale simulation and forward design method and system for interlayer fracture toughness of a particle toughened composite material, and belongs to the technical field of electric digital data processing. According to the method, a three-dimensional representative volume element (RVE) model containing randomly distributed spherical particles is constructed, an elastic-plastic constitutive model and a progressive damage model are given to the model, and a microscopic toughening mechanism is accurately represented in combination with periodic boundary conditions; a macroscopic double cantilever beam (DCB) model fused with mesoscopic characteristics is established, crack initiation and expansion are simulated by adopting an expansion finite element (XFEM) method, and cross-scale forward prediction from mesoscopic parameters to macroscopic I-type interlayer fracture toughness is realized. According to the method, the problems that a traditional trial and error method is long in research and development period and high in cost and an existing simulation model is distorted in simplification, disjointed in scale correlation and the like are solved, the design can be optimized by adjusting parameters such as the particle size and the volume fraction, and a reliable theoretical tool and a design system are provided for interlayer toughening design of the high-performance composite material.

The utility model discloses a double-cantilever type high-precision force measurement sensing device which comprises a base, a groove is formed in the middle of the base, and an elastic body is fixed in the groove; the elastic body comprises a fixed table, the fixed table is fixed in the groove, cantilever beams which are symmetrically distributed left and right are arranged on the side edge of the fixed table in an extending mode, and the bottom of the fixed table protrudes downwards relative to the cantilever beams. The sensor has the advantages that the weighing platform area of the sensor can be increased through the bilaterally symmetrically distributed double-cantilever beam structure, the eccentric influence of the sensor caused by different detection positions is reduced, and the sensor can meet many high-precision force measurement scenes.

The invention relates to a bonding device for precisely centering a double-cantilever-beam hinge and enabling the double-cantilever-beam hinge to be consistent with a glue layer in thickness, in particular to a device for bonding a test piece hinge in a double-cantilever-beam test. The invention aims to provide a device capable of assisting in hinge adhesion before a double-cantilever beam test so as to realize consistent thickness of a hinge adhesive layer on a pre-cracking side of a test piece, and the device comprises a workbench, a synchronous belt power input module, a hinge adhesion clamping module and a sample piece cam bias module. The workbench is used for connecting and bearing basic platforms of other mechanisms; the synchronous belt power input module is used as a power input mechanism; the hinge bonding and clamping module is used for keeping the bonding state of the hinge and the test piece; and the sample piece cam offset module is used for uniformly smearing the adhesive layer. By means of the structure, the hinge pasting efficiency is remarkably improved, the production cost is reduced, and accurate centering pasting of the hinge on the sample piece and consistent thickness of a pasting adhesive layer are achieved.

The invention belongs to the technical field of micro-nano structure mechanical property testing, and aims to solve the problems that in the prior art, the dynamic expansion path of micro cracks in an integrated circuit multi-layer interconnection structure cannot be monitored in a three-dimensional mode in real time, and the nanoscale energy release rate cannot be quantitatively evaluated. The invention provides an in-situ monitoring method integrating a miniature double-cantilever beam mechanical testing device and a synchronous X-ray nanometer tomography system. According to the core scheme, three-dimensional shape data of crack propagation are obtained in real time by designing a sample clamp coupled by an asymmetric double-cantilever beam interface and combining a high-resolution X-ray imaging system, and a quantitative correlation model of a crack tip stress field and an energy release rate is established through a data reconstruction algorithm. Compared with a traditional electron microscope detection technology, the method has the advantages that the micro-crack monitoring resolution ratio can be increased to 100 nm or below, active guiding control over the crack path is achieved, and the critical energy release rate of the sub-hundred-nanometer area can be quantitatively measured on the premise that the sample stress state is kept.

A double-cantilever-beam type tension sensor relates to the technical field of force measuring structures and comprises a sensor base, a sensor elastic body is fixed on the sensor base, the sensor elastic body forms two sensor deformation beams through a U-shaped notch, metal strain gauges are fixed on the inner walls of the two sensor deformation beams respectively, and the metal strain gauges are arranged on the two sensor deformation beams. And two groups of bearing assemblies are rotationally arranged at the end parts of the two sensor deformation beams respectively. The utility model solves the problems that in the prior art, a conventional tension sensor is relatively large in size, a textile machine is relatively compact in structure and small in space, the conventional sensor cannot be installed, the conventional textile machine is not provided with tension detection, the tension can only be controlled by experience, the control and adjustment are empirical, and the conventional tension sensor cannot be installed on the textile machine. And no data can be speaked, so that the uniformity of the quality of the finished product cannot be consistent.

The invention discloses a semi-analytical method and DCB test super-hybrid composite material I-type layering behavior characterization method, and particularly relates to the technical field of composite material mechanics. The method comprises the following steps: firstly, carrying out mechanical analysis on a double-cantilever beam sample by utilizing a Timoshenko beam theory, and deducing an analytical expression of a displacement field, flexibility and total fracture toughness; and reversely and synchronously identifying the bending modulus Ef and the shear modulus G13 of the material through flexibility measurement values under different crack lengths. According to the method, J integration irrelevant to an integration path is introduced, an index type bridging stress function is combined, contribution of fracture toughness of a crack tip and a fiber bridging area is clearly separated, and accurate energy analysis of the whole layered expansion process is achieved. According to verification of CFRP / TC4 and GFRP / TC4 super-hybrid composite material systems, results show that the method can efficiently and accurately obtain the I-type interlayer fracture toughness R curve and the bridging stress.