98 results about "Micro damage" patented technology

The invention provides a traffic tunnel crack plugging and reinforcement method used in a vibration-disturbed environment, and relates to the technical field of crack repair in traffic tunnels. The grouting material is poured by using the method of minimal damage and adopting the pinhole oblique side drilling method. , Reinforcing while plugging. The specific method is to use a cutting machine to cut grooves along the seam first, clean them up and fill them with special cement for sealing, then make grouting holes along both sides of the seam to 1/3 to 1/2 of the seam. The grouting nozzle is installed in the hole, the grouting material is injected, and through the sealing effect of the cutting groove, and through the cross grouting, the grout is injected into the depth of the crack, so that the lining concrete at the crack is restored to form a whole, which solves the existing problems in the prior art. The technical problem that underground engineering cannot effectively plug leaks in the vibration-disturbed environment prevents leakage and cracking due to vibration-disturbed deformation and damage, and restores the compactness and structural integrity of the lining concrete.

The invention relates to a new rock mass damage constitutive model construction method, comprising the following steps: step S10: based on strain equivalence principle, adding a bearing capacity coefficient of a damaged material to obtain a modified rock damage constitutive model; Step S20, respectively calculating a macro damage tensor of the joint and a micro damage variable of the micro crack,and establishing a mechanical model of the macro damage and the micro damage of the joint rock according to the superposition principle; Step S30: According to the damage mechanics theory, constructinga rock mass damage constitutive model with coupling of macroscopic defects and microscopic defects. The novel rock mass damage constitutive model construction method and device provided by the invention provide a simple principle, The damage constitutive model of rock mass, which is easy to operate and low in cost, is reasonable and reliable considering the coupling of macroscopic and microscopicdefects. The mining range can be delineated accurately and reasonably by using the damage constitutive model in the design of excavation slope engineering.

The invention discloses a nonlinear ultrasonic guided wave detection method and a nonlinear ultrasonic guided wave detection device for pipeline micro damage. An exciting transducer capable of exciting single guided wave modal state and a matched receiving transducer are adopted, the transducers can wind a pipeline to excite axisymmetric modal states, the receiving efficiency of a second order harmonic signal is improved by a matching and corresponding receiving probe, the detection capacity of the system on second order harmonic waves of the guided waves is improved. The nonlinear change of a material is characterized by detecting the ratio of nonlinear response to propagation distance, nonlinear interference of instruments is effectively reduced, nonlinear ultrasonic guided wave evaluation of the pipeline material is realized, and nonlinear ultrasonic high sensitivity can be used for early detection of the pipeline micro defects.

The invention discloses an online real-time monitoring method and system for structural damage. According to the method or the system, a set empirical mode decomposition algorithm is utilized on microvibration response signals in the direction perpendicular to a structure to obtain a first stage natural frequency and a second stage natural frequency, and whether the first stage natural frequency and the second stage natural frequency are equal to a natural frequency of an undamaged structure is judged; if so, that the surface of the structure is not damaged is determined; if not, that the surface of the structure is damaged is determined, and energy values of different measurement points of different slide times are calculated out; whether the energy value of some measurement point of different slide times is equal to that of a corresponding measurement point of the undamaged structure is compared; if so, that the measurement point is not damaged is determined; if not, that the measurement point is a damaged position is determined. Therefore, the method or the system disclosed by the invention can be used for detecting transient micro damage of the structure and determining the damaged position in real time under the high-frequency and high-speed background conditions.

The invention relates to nondestructive testing, and provides an ultrasonic micro-damage location detection method based on collinear aliasing of Lamb waves. The method comprises the following steps: (A), a pair of Lamb wave mode combinations with different frequency and propagation modes is determined; (B), generated difference frequency harmonic waves of the Lamb waves are determined; (C), the pair of initial Lamb wave modes are excited by signal excitation units; (D), a signal receiving unit having corresponding frequency with the difference frequency harmonic waves is selected to receive the difference frequency harmonic waves; (E), an area where beams start for aliasing is confirmed; (F), positions of two initial excitation sources are changed; (G), scanning detection is performed on a tested object; and (H), the micro-damage location of the tested object is calculated and confirmed according to amplitude change of the difference frequency harmonic waves. The invention further provides an ultrasonic micro-damage location detection device based on the collinear aliasing of the Lamb waves. The device comprises a first computer, a signal generator, a first signal excitation unit, a second signal excitation unit, a signal receiving unit, an oscilloscope and a second computer. The ultrasonic micro-damage location detection method and device are applied to material detection.

The invention discloses a method for measuring residual stress on surface of a metal sample based on micro indentation. The method comprises the following steps: performing a micro indentation test on the surface of the sample by utilizing a Vickers microhardness tester, recording the indentation morphology by adopting a scanning electron microscope, and obtaining the nominal projection area and actual projection area of the indentation on the surface of the sample through calculation for diagonal length and side length of the micro indentation; obtaining a strength coefficient and strain hardening index of the material through a standard tensile test; and obtaining a theoretical formula for measuring the residual stress through an indentation method and containing the ratio of the actual projection area to the nominal projection area of the micro indentation, the strength coefficient and strain hardening index based on the hypothesis for the two-dimension isometric residual stress field on the surface of the sample, and further obtaining the residual strain and residual stress on the surface of the sample. The measurement method belongs to basically nondestructive or micro-damage measurement and has the advantages of low measurement cost, simplicity and convenience in operation and high measurement efficiency. If being combined with a portable high-power optical microscope with a distance measurement function, the method can be popularized and applied in the field of engineering.

The invention discloses a concrete anti-cracking reinforced self-repairing material and a preparation method and application thereof, and relates to the technical field of building materials. The concrete anti-cracking reinforced self-repairing material is prepared from the following raw materials in parts by weight: 40 to 60 parts of dense component, 10 to 30 parts of water storing component, 10 to 20 parts of plastifying component, 2 to 8 parts of complexing component, and 4 to 20 parts of thickening and reinforcing component. By adopting the concrete anti-cracking reinforced self-repairing material, the crack resistance of a substrate can be improved, micro-cracks or micro-damages which are not greater than 0.4mm in a concrete hardened body due to various causes can be repaired continuously, and continuous increase in the strength of the substrate after repairing of the cracks can be facilitated.

A quantitative assessment method for stone cultural relic component weathering and security degree includes the following steps: selecting physical properties which can be achieved through lossless or micro-damaged detecting and capable of reflecting features of rock weathering and security as evaluation indexes according to protective principles of cultural relics, distributing corresponding weighted values to all the evaluation indexes through an expert scoring method to reflect degree of impact of different indexes to the component weathering and the security degree, dividing weathering degree into five levels and the security degree into four levels and formulating point values for all levels, preliminarily determining the weathering degree and the security degree according to a single evaluation index, and adopting a point weighting method to calculate final weathering points and security points of all the components to achieve the weathering degree and the security degree of the component visually and accurately.

The invention provides an SF6 high-voltage circuit breaker polytetrafluoroethylene composite material nozzle which is composed of the components of, by mass, 1-8% of boron nitride (BN), 0.1-0.4% of molybdenum disulfide (MoS2), and balance of polytetrafluoroethylene (PTFE). According to the invention, MoS2, BN, and PTFE are compounded for preparing a nozzle which can resist high voltage and large current arc ablation. When the nozzle composed of the composition is in use, during a thermal cracking process controlled by heat, the BN component can reduce the decomposition speed of PTFE. When PTFE is decomposed due to arc ultraviolet light, the filling material containing MoS2, short-wave ultraviolet can be blocked and absorbed, such that the ablation of the composite material and local micro-damage on the surface of a nozzle throat can be retarded. The nozzle is suitable to be used in extra-high-voltage circuit breaker products and ultra-high-voltage circuit breaker products. With the material, the service life of the nozzle, which is a core component, can be prolonged.

The invention provides a method for detecting temperature of the side wall of a small-bore micro-damage crucible of a blast furnace on line, and belongs to the technical field of blast furnace smelting crucible detection. The detecting method comprises the following steps that: 1) a blast furnace to be detected comprises a furnace shell, a cooling wall and carbon bricks, and padding is filled between the furnace shell and the cooling wall and between the cooling wall and the carbon bricks respectively; 2) detecting points and depths of the detecting points are determined, the detecting points are respectively distributed in clearances of the cooling wall on the side wall of the crucible, and the depths of the detecting points are determined according to a medium to be detected and the thickness of the medium; 3) the surface of the furnace shell of the crucible to be detected is provided with horizontal holes according to the detecting points and the depths of the detecting points determined in the step 2); 4) a thermocouple with a sheath is placed in a horizontal hole, a sealing element is fixed on the furnace shell, and the thermocouple with the sheath is fixed on the crucible to be detected; and 5) the thermocouple and PLC are connected through a thermocouple lead wire to realize real-time detection and acquire solid temperature variation gradient. The method has the characteristics of simpleness, convenience, reliability, less investment, less maintenance and installation without blast furnace overhaul.

The invention discloses a magnetic memory detection device of oil drill rod micro-crack including: rack and testing ring. The testing ring is set up on the rack and can be installed on the drill rod. The testing ring has the magnetic memory sensor used for testing the described drill rod; the rack has the first driving device used to drive the rack move along the axial direction of the drill rod on the rack. The invention can achieve the non-contact non-destructive test on the micro-damage and stress concentration of oil drill rod in order to provide a basis for drill rod classification management. It mainly features: no special magnetic device, small size and light weight.

The invention discloses a manufacturing method for a two-layer silicon epitaxial wafer used for a bipolar transistor. Compared with a manufacturing method for a conventional two-layer silicon epitaxial wafer, the manufacturing method for the two-layer silicon epitaxial wafer used for the bipolar transistor is characterized by comprising the following steps of removing micro damages of the surface of a silicon wafer by using a hydrogen chloride (HCl) polishing process before a first layer silicon epitaxial wafer is grown; taking out the silicon wafer after the first layer silicon epitaxial wafer is grown to perform etching treatment on a system; and cleaning the silicon wafer before a second layer is grown to ensure the surface to be clean, removing the micro damages of the surface by using the HCl polishing process, and removing impurities by using hydrogen (H2) after polishing. According to the manufacturing method, a reaction chamber etching step is inserted, and therefore, the uniformity and the repeatability of the electrical resistivity of an epitaxial layer are ensured, and the performance and the finished product rate of a device are ensured.

The invention discloses a speed reducing device for retrieving a high-speed flight body with slight damage, and belongs to the technical field of buffer protection. The speed reducing device is a speed reducing device for retrieving the high-speed flight body with slight damage through non-isopycnic air and water mixtures, and the flying speed of the high-speed flight body ranges from 50 m/s to 500 m/s. The speed reducing device is composed of a retrieval box, water, bubbles, a bubble generator, a felt pad, rubber, springs, a water pool and the like, wherein the water, the bubbles, the bubble generator, the felt pad, the rubber and the springs are arranged in the retrieval box, the retrieval box is placed into the water pool, the bubbles are generated by the bubble generator, a buffer and speed-reducing mechanism is formed by non-isopycnic air and water mixture space in the forwarding direction of the flight body from the edge of the front wall of the interior of the retrieval box, a retrieval protection mechanism is formed by the felt pad on the rear portion of the retrieval box, the rubber and the springs, and the water pool is used for recycling water which overflows after the high-speed flight body penetrates through film on an inlet of the retrieval box. The speed reducing device has the advantages that the non-isopycnic air and water mixtures are used for effectively buffering the high-speed flight body, the structure of the flight body is slightly damaged, it can be ensured that the speed of a high-speed flying object is evenly reduced under the condition of small acceleration, the speed reducing device has the advantages of being simple in structure, convenient to use and reliable in retrieval, and the speed reducing device for retrieving the high-speed flight body with slight damage is worthy of application and popularization.

The invention discloses a near field phased array structure health monitoring method based on a piezoelectric array. The method comprises the following steps: arranging a piezoelectric linear array on a monitoring structure so as to obtain a damage scattering signal of each excitation-sensing channel, adding time delay to a damage signal, and determining the damage direction; and finally, determining the damage position according to a signal arrival moment t. With the adoption of the near field phased array structure monitoring method disclosed by the invention, micro damage in a complex structure can be identified, and the limitation of a far field phased array on the monitoring distance is overcome.

The invention discloses a rear tong head clamping mechanism of a micro-damage screwing machine. The mechanism consists of a rear tong head main body, a lower jaw plate rack, an upper jaw plate rack, jaw plates, tooth blocks, rollers, roller shafts, return springs, a fixed shaft, a fixed shaft sleeve, a rear tong head gear ring, a motor gear, a hydraulic motor and the like. The mechanism is structurally characterized in that: three or more jaw plates are arranged in the rear tong head main body; the roller shafts, the rollers, the tooth blocks and the return springs are arranged on the jaw plates; the inner curved surface of the rear tong head main body is provided with a working arc; and the lower jaw plate rack, the upper jaw plate rack and the rear tong head gear ring are connected into a whole by the fixed shaft, the fixed shaft sleeve and screws. The mechanism is a simple and reliable inner curved surface roller climbing multi-jaw plate clamping mechanism, the tooth blocks are made of abrasion-resistant material, and the contact area of the tooth blocks and tubular columns is enlarged so that the tooth blocks play a role in clamping the tubular columns without damaging the tubular columns; and the system has considerable economic benefit.

The invention discloses enhanced anti-cracking self-repairing concrete and a preparation method thereof, and relates to the technical field of building materials. The concrete is C30 concrete and comprises, by weight, 154-164 parts of cement, 36-44 parts of fly ash, 262-290 parts of fine aggregates, 613-677 parts of coarse aggregates, 41.8-46.2 parts of water, 1.6-2.2 parts of fibers, 7.6-16.8 parts of repairing agents and 18-20 parts of anti-cracking anti-seepage agents. The concrete improves crack resistance and can effectively restrain cracking and continuously and automatically repair micro-cracks or micro-damage of the concrete caused by various reasons, the mechanical property of the concrete before being damaged can be recovered, economy and durability of the concrete are improved,and the service life of the concrete is prolonged.

The invention discloses an electrolytic machining method for maintaining and remanufacturing of an aeroengine. The electrolytic machining method for maintaining and remanufacturing of the aeroengine comprises the first step of study on the electrolytic machining mechanism of titanium alloy, the second step of design and preparation of a cathode, the third step of preparation of a special electrolyte, the fourth step of acquisition of technological parameters in the electrolytic machining process, the fifth step of study on precision control of electrolytic machining, the sixth step of study on the influence of flow field distribution of the electrolyte, and the seventh step of establishment of an electrolytic machining quality evaluation system. According to the electrolytic machining method for maintaining and remanufacturing of the aeroengine, the electrolytic machining technique is used for replacing a traditional machining method to meet technical requirements for machining of molded surfaces of key components of the civil aeroengine, so that secondary damage such as micro-cracks, micro-scratches and generated mechanical stress, caused by the traditional machining method, to a machined surface is avoided. The electrolytic machining method is used as the machining basis for welded titanium alloy structural components, so that influences such as overheating, a cold working layer, mechanical stress and micro-damage to the surface can be avoided while a redundant surfacing layer is removed; and meanwhile, the influence of feeding limitation of the traditional machining method can be avoided, the machining time is greatly shortened, and economic cost is reduced.

The invention relates to a device for detecting damage depth of an object surface scratch and belongs to the technical field of measurement. The device for detecting the damage depth of the object surface scratch comprises an illuminating system, an observing system, an imaging system, a mechanical system and a data processing system. Working steps include stable arrangement of the detecting device, confirmation of observing direction, adjustment of an image to be observed and acquisition and quantitative analysis of the image. The device can quantitatively measure the depth of the object surface scratch and measure the depth value of 0.002mm of micro damage, adopts non-contact measurement, and does not produce secondary damage to a measured object. A measurement value can trace to the source, the detecting device is small in volume, convenient to read and simple in operation, and an adopted ball head support screw is suitable for object surfaces with various shapes. The device for detecting the damage depth of the object surface scratch is suitable for field inspection of local damage of large parts.

The invention discloses damage diagnosis equipment for truss structure, which comprises wireless strain sensors, a wireless data acquisition instrument and a rod damage state diagnostor, wherein the wireless strain sensors are mounted at the middle parts of rods; the wireless data acquisition instrument can regularly acquire strain values of the rods under the same dynamic conditions of the truss structure and transmit the strain values to the rod damage state diagnostor; and the rod damage state diagnostor comprises a strain variance ratio module, a comparison and diagnosis output module and a voltage-stabilizing module. According to the method disclosed by the invention, only the one set of wireless data acquisition instrument and the plurality of wireless strain sensors are required, the operation is easy to implement, micro damage can be detected, and long-term monitoring of normal operation state of the truss structure is realized. The technical scheme provided by the invention is simple in structure, low in cost, easy to operate and implement, can detect the micro damage, and can monitor the normal operation state of the truss structure for a long term.

The invention belongs to the technical field of polymer materials, and discloses an ethylene-propylene-diene monomer composite elastomer and a preparation method thereof. The preparation method comprises the following steps: adding EPDM (ethylene-propylene-diene monomer), an initiator, MAH (maleic anhydride) and St (styrene) into a mixing device for carrying out mixing, so as to obtain MAH-g-EPDM;adding the MAH-g-EPDM, ATA (3-amino-1,2,4-triazole) ligands and an antioxidant into the mixing device for carrying out mixing to obtain ATA-functionalized EPDM; and carrying out uniform mixing on theATA-functionalized EPDM, a zinc chloride metal salt and a vulcanization system, and then carrying out vulcanization to obtain the ethylene-propylene-diene monomer composite elastomer. According to the invention, through the construction a dynamic cross-linking network structure with multiple hydrogen bonds and metal-ligand coordination and the synergy of a covalent bond chemical cross-linking network, the strength and toughness of the EPDM is enhanced, the rubber viscoelasticity is effectively adjusted, the damping performance of the EPDM is improved, a self-repairing property is provided tothe material, micro-damage can be repaired autonomously under a heat environment, and the service life is prolonged.

The invention discloses bionic self-repairing concrete and a preparation method thereof. The bionic self-repairing concrete is characterized by being prepared from the following raw materials in partsby weight: 240 to 360 parts of cement, 180 to 250 parts of active admixture, 1300 to 1600 parts of aggregate, 60 to 90 parts of mesoporous bioactive glass composite microspheres, 20 to 30 parts of calcium peroxide microspheres, 20 to 30 parts of carbon nanotubes, 8 to 16 parts of polycarboxylate water reducing agent and 190 to 220 parts of water. The bionic self-repairing concrete provided by theinvention has a rapid self-repairing capability, can continuously and automatically repair micro-cracks or micro-damages of different deep layers in the concrete, promotes the continuous increase ofthe matrix strength after crack repairing, and improves the strength and durability of the concrete. The self-repairing concrete has the advantages of being wide in repairing range, rapid in repairingand lasting in repairing.