78 results about "Secondary stress" patented technology

The invention provides a finite element analysis method for the temperature action on a prestressed reinforced concrete continuous rigid frame bridge. The finite element analysis method is used for analyzing and calculating the stress and displacement distribution in the construction and finished bridge stage under different temperature gradient models, and provides references for designing and optimizing the prestressed reinforced concrete continuous rigid frame bridge. Through calculational analysis based on finite elements and the structural mechanics, the forward-calculation method is adopted for structural distortion and stress analysis according to the actual construction loading sequence of the bridge structure, so that the complex mechanics problem of box girder temperature self-stress, temperature secondary internal force in a prestressed reinforced concrete statically indeterminate structure and secondary stress of the temperature secondary internal force is solved easily, conveniently and efficiently, and the finite element analysis method has important practical value.

The invention relates to an aluminum alloy section of a secondary stress member of an automobile bumper and a preparation method thereof. The invention is characterized in that the 6060 aluminum alloy material of the member comprises the following components in parts by weight: 0.56-0.58 part of Mg, 0.32-0.35 part of Si, no more than 0.2 part of Fe, no more than 0.02 part of Mn, no more than 0.02 part of Cu, no more than 0.02 part of Ti, no more than 0.03 part of Zn, no more than 0.03 part of Cr, and the balance of Al. The preparation method comprises the following steps: preparing an aluminum alloy round ingot from the raw materials; extruding a section and placing the section in an aging thermal treatment furnace within 48 h, wherein the aging temperature is between 165 and 170 DEG C; and preserving heat for 3.5 h and then performing the aging thermal treatment. The invention has the beneficial effects that by introducing alloy elements, the precipitation phase number is selectively controlled and a proper amount of precipitation phase distribution is formed; the special requirements on the mechanical property of the secondary stress member of the automobile bumper can be satisfied; and batch production can be realized.

Disclosed herein is a method of preventing corrosion degradation in a defective region including an expansion transition region and/or an expansion region of a heat transfer tube of a steam generator in a nuclear power plant by using nickel (Ni) plating or nickel (Ni) alloy plating. The method can prevent various types of corrosion damage, such as pitting corrosion, abrasion, stress corrosion cracking, lead-induced stress corrosion cracking and the like, occurring during the operation of the steam generator, and particularly, pitting corrosion or primary and secondary stress corrosion cracking, so that the life span of the steam generator is increased, maintenance costs are reduced, and the operation rate of a nuclear power plant is increased, with the result that the unit cost of the production of electric power can be decreased, thereby improving economic efficiency. Further, the method can be usefully used to prevent the corrosion damage of parts and equipment of nuclear, hydroelectric or thermoelectric power plants or of petrochemical plants, and that of industrial and machine parts and equipment, and parts and equipment in a defense industry.

The invention discloses a crack-substrate coupling flow damage evaluating device and method by simulating formation conditions. The device mainly consists of a kettle body 4, a rock core 1, a crack 6, a simulated well 7, a pressurized capsule 3, a resistance probe 16, a pressure sensor 18, a data collecting system 17 and a work liquid circulation system, wherein the rock core 1 is arranged in the kettle body 4; the pressurized capsule 3 wraps the periphery of the rock core; the kettle body is provided with an axial pressure injecting opening, a peripheral pressure injecting opening and a gas inlet; the crack 6 and the simulated well 7 are arranged in the rock core; nine drilling holes extending into the rock core are distributed in the rock core; the resistance probe 16 is arranged in the drilling holes; the resistance probe 16 is connected with the pressure sensor 18; the resistance probe and the pressure sensor are connected with the data collecting system 17; the simulated well 7 is connected with the work liquid circulation system. The circum-well secondary stress condition and the formation radial flow of a crack-substrate system are simulated for determining the damage degree of the crack-substrate system by the device. The device and the method have the advantages that the principle is reliable; the operation is convenient; scientific and accurate quantitative reservoir damage evaluation can be made.

The invention relates to a processing technology of a large-radian arc-shaped spring. The processing technology is characterized by comprising the following procedures of: spring coiling: primary stress relief annealing; spring grinding; spring bending into an arc-shaped spring; secondary stress relief annealing; shot blasting; hot-strong pressing; sorting; angular rigidity and torque test; fatigue life test; and surface antirust treatment. According to the forming technology of the arc-shaped spring provided by the invention, the arc-shaped spring with the free angle of being more than 45 degrees can be effectively formed, the thermal relaxation rate of the spring is less than 2%, the instantaneous torque is large, the fatigue life is 1 million times, and the technical problems of low finished product rate and incapability for normal use of the large-radian arc-shaped spring in the prior art are solved.

The invention discloses a composite bridge deck applied to long-span bridges and city bridges. The composite bridge deck comprises a bridge deck body, wherein the bridge deck body is formed through combining a lower wave-shaped steel plate and an upper concrete slab; shear connectors which are symmetrically welded to wave crests of the wave-shaped steel plate upwards extend into the concrete slab; reinforcing steel bars and annular hoop reinforcements which are used for bundling up the reinforcing steel bars are arranged at the middle part of the concrete slab in a balanced manner. According to the composite bridge deck, the characteristics of the wave-shaped steel plate and the characteristics of the concrete slab are combined together, properties of materials are fully utilized, the flexural bearing capacity is enough under heavy loads, the deformation is small enough under the action of concentrated loads, and too-large secondary stress resulting from weld seams can be avoided; a top plate of a steel bridge deck is replaced with the concrete slab, so that the construction cost of a bridge floor system can be reduced; the quantity of welding is very small, so that the damage to the bridge deck caused by defects of a welding process can be reduced; due to the wrinkling effect of the wave-shaped steel plate, the problem that the deformation of the steel plate and the deformation of concrete are non-synchronous can be greatly solved, and the cracking of the transverse bridge direction of the bridge deck is avoided.

The invention discloses an inverse U-shaped overhead monorail traffic track girder which comprises a track girder U-shaped body and bottom plates, wherein the bottom plates include a first bottom plate and a second bottom plate, and the first bottom plate and the second bottom plate are welded at the bottom of the track girder U-shaped body; the first bottom plate comprises a first track girder bottom outer flange and a first track girder bottom inner flange; the second bottom plate comprises a second track girder bottom outer flange and a second track girder bottom inner flange, and the second track girder bottom outer flange and the second track girder bottom inner flange are fixed; and the track girder U-shaped body is molded by rolling or bending. The track girder disclosed by the invention is convenient for construction transportation and field installation, the flatness of the inner section of the track girder is guaranteed, and the comfort degree is high. According to the invention, primary and secondary stress regions are divided, wherein the track girder bottom flanges which have relatively large stress can be integrally molded by rolling or bending by adopting relatively thick steel plates, and the other regions which have relatively small stress can be integrally molded by rolling or bending by adopting relatively small-thickness steel plates, thereby being favorable for reducing the steel consumption, reducing the welding workload and improving the processing and manufacturing efficiency.

The invention provides a historic building slanting timber frame tensioning jacking resetting device which comprises a box body, a ground support, a round bearing table, mechanism arms composed of a vertical arm and a cross arm, a linear displacement amplifying device and an electric winch, an auxiliary jack, a power jack, a universal joint and a variable hoop which are arranged in the box body. A jacking system composed of a hydraulic pump station with a proportional pressure dividing valve and a large-stroke jack and a tensioning system composed of the electric winch, a steel strand and the linear displacement amplifying device are utilized to conduct tensioning and jacking resetting operation on a historic building slanting timber frame. Force transfer condition between the back shore system and the timber frame to be repaired is effectively improved through the universal joint and the variable hoop to achieve steering of a correction force system, secondary stress is greatly reduced in the correction, stress performance of a column head is improved, the column head is protected, and secondary damage caused by concentrated stress caused by the fact that the force system directly acts on the column head in the correction is avoided.

A PFET is provided on a silicon layer having a (110) surface orientation and located in a substrate. A compressive stress liner disposed on the gate and source/drain regions of the PFET generates a primary longitudinal compressive strain along the direction of the PFET channel. A tensile stress liner disposed on at least one NFET located transversely adjacent to the PFET generates a primary longitudinal tensile strain along the direction of the NFET channel. A secondary stress field from the at least one NFET tensile liner generates a beneficial transverse tensile stress in the PFET channel. The net benefits of the primary compressive longitudinal strain and the secondary tensile transverse stress are maximized when the azimuthal angle between the direction of the PFET channel and an in-plane [1 10] crystallographic direction in the (110) silicon layer is from about 25° to about 55.

The invention discloses a transient unloading test simulation system for deep fractured rock mass under a high confining pressure. The system mainly comprises a rock mass model, a support frame body,a test bench, a horizontal loading device, a vertical loading device, a loading and unloading device and a monitoring device, wherein the rock mass model is arranged in the support frame body, and thesupport frame body is arranged on the test bench; the bottom and left side of the rock mass model are jointed with the inner wall surface of the support frame body, and the right side of the rock body model is connected with an output end of the horizontal loading device; the top of the rock body model is connected with the vertical loading device; the loading and unloading device passes throughthe support frame body, and is connected with the lower part of the right side face of the rock mass model; an input end of the monitoring device is connected with the rock mass model. The transient unloading test simulation system for deep fractured rock mass under the high confining pressure has the beneficial effects that the system can realize a simulation test capable of simulating the following two mechanisms: transient redistribution, caused by transient unloading of surrounding rock, of a secondary stress field during blasting excavation; local damage possibly caused by quasi-static change of secondary stress field due to surrounding rock creep; therefore, the transient adjustment of the secondary stress field is realized, and the system is more in line with actual unloading situation in a project.

The embodiment of the invention provides a novel layered slope earthquake damage instability calculating system and method based on an energy demodulation frequency spectrum, and relates to the geological technical field; the system comprises the following parts: a seismic wave time travel curve module used for obtaining a seismic wave time travel curve; a STFT demodulation curve module used for obtaining reflection wave and penetrated wave each order typical frequency time travel curve and energy spectrum curve; a multi-earthquake excitation module used for carrying out multi-earthquake excitations in a frequency domain; a secondary stress redistribution module used for calculating secondary stress redistribution; a structural slope partitioning stress calculation module used for solvingthe average stress state on each interface, drawing a sliding mass structural surface stress field, horizontally and transversely stripping the slope, and solving the lower sliding force and anti-sliding force of corresponding positions on the strip interfaces; a damage mode analysis module used for analyzing damage modes; a stability state evaluation module used for evaluating stability states. The method and system are high in calculating efficiency and accuracy.

The invention relates to a modular splicing type copper alloy stretching net box and n assembling method thereof. The modular splicing type copper alloy stretching net box comprises a vertical main stressing high-strength polyester fiber belt main framework tape standard part and a horizontal secondary stressing high-strength polyester fiber belt secondary framework tape standard part which are fixed at a crisscross connecting point to form a grid shaped single-side net box tape framework which has the characteristics of flexibility and elasticity; a prefabricated copper alloy stretching net standard module is assembled into each frame of the grid shaped single-side net box tape framework through a prefabricated quick connecting part to form the modular splicing type net box body single-edge side net; two side edges of the single-edge side net are connected through the quick connecting part, or a plurality of single-edge side nets are provided with corner flexible connecting adapting standard parts and bottom nets and then assembled to be a copper alloy stretching net box body. The modular splicing type copper alloy stretching net is applicable to modular and standard production and convenient to be quickly mounted in the sea; a marine breeding net can be maintained well and prevented from being attached by marine fouling organisms; the inside and outside water of the net box body can be exchanged well.

The invention relates to a method for simplifying analysis of elastic-plastic fractures of a reactor pressure vessel (RPV) under extreme accident conditions based on RCC-M specification. The method comprises the following steps: (a) analyzing loads of extreme accident conditions and dividing various loads into primary stress loads and secondary stress loads by determining whether the loads have influence on plastic instability of the structure; (b) determining types and shape parameters of fissures according to RCC-M specification; (c) obtaining material property parameters of RPV and calculating a linear elastic stress intensity factor, wherein the linear elastic stress intensity factor is sum of stress intensity factors caused by the primary stress loads and the secondary stress loads in transient state; and (d) judging whether the RCC-M specification is applied to plastic correction of the linear elastic stress intensity factor, assessing by using the technology when the plastic correction of the linear elastic stress intensity factor exceeds the application range of the RCC-M specification so as to improve accuracy of analysis of fracture-containing defects of RPV.

The invention discloses a veneer special for a wood blade of a classical ceiling fan and a preparation method for the plywood. The preparation method comprises the following steps of: preparing materials, wherein thickness difference between a eucalyptus core veneer and a eucalyptus long-center veneer is not more than 0.3mm; assembling; hot-pressing, namely performing hot-pressing on a three-layer blank veneer subjected to cold repair; hot stacking for 24 to 72 hours to cure glue water and eliminate stress; cutting an edge, supplying putty, sanding and veneering; hot-pressing the veneered 5-layer veneer; cooling, and hot staking for 2 to 3 days; cutting an edge; performing humidifying and formaldehyde pollution resistant posttreatment; eliminating secondary stress; and performing surface treatment and wood grain filling to obtain the veneer special for the wood blade of the classical ceiling fan. The veneer special for the wood blade of the classical ceiling fan has the advantages of small deformation, high integral strength, flat and smooth surface and no torn grains.

The invention relates to the field of performance measurement of steel stamped parts and in particular to a method for measuring the volume distribution of retained austenite in a transformation induced plasticity (TRIP) steel stamped part. The method for measuring the volume distribution of retained austenite in the TRIP steel stamped part comprises the following steps of: firstly classifying the deformations into four standard deformation modes; then deducing the law of retained austenite transformation under a complicated strain path according to the plastic deformation theory; and finally calculating the volume content of retained austenite of each point on the part after deformation according to the main and secondary strain magnitudes. The method can be used for obtaining the volume content of retained austenite only by measuring the main and secondary stresses of the stamped part; has the advantages of simplicity of implementation, accurate result and low time and economic costs; and provides a basis for improving the formability of the TRIP steel by improving the part shape and the process addendum and/or the design of draw beads, so as to take full advantage of the effect of transformation induced plasticity of the TRIP steel and increase the application range of the TRIP steel.

The invention discloses an anti-jamming single-shield TBM main machine structure and an anti-jamming method thereof. The anti-jamming single-shield TBM main machine structure and the anti-jamming method thereof are used for solving the technical problem that in the prior art, jamming is easily caused on single-shield TBM faults, crushed zones and other poor stratums. The anti-jamming single-shield TBM main machine structure comprises a cutterhead. The cutterhead is connected with a shield body. The shield body comprises a front shield, a middle shield and a tail shield which are sequentially connected. Multiple detachable front shield check pulp brushes are arranged at the front end of the front shield, multiple upper tail brushes and multiple lower tail brushes are arranged on the shield wall of the rear end of the tail shield, the upper tail brushes correspond to the front shield check pulp brushes, multiple trigger mud connectors are arranged on the shield walls in the front shield and the tail shield, the trigger mud connectors are connected with a mud storage tank through a mud pipe, and a mud conveying pump is arranged on the mud pipe. The positions between dug cavity walls and the shield body are filled with trigger mud, a stress field generated after the cavity walls are dug is converted into a tertiary stress state from a secondary stress field, the stratum deformation rate is reduced accordingly, a single-shield TBM can smoothly and stably pass through a crushed stratum, and construction quality and construction safety are guaranteed.

A hydraulic flange connection formed on a tube having a first groove formed in the outside of the flange at a first stress area and a second groove formed in the outside surface of the flange at a secondary stress area and extending in a direction substantially perpendicular to a central cavity formed in the tube.

The invention discloses an engineering calculation method of a flexible thin tube sheet, comprising the following steps: determining the wall temperature of a heat exchange tube and the design temperature of a channel box; according to the technological condition, optimizing the tube pitch of key structural parameter and the wall thickness of the heat exchange tube; analyzing and processing a calculation result; if secondary stress is out of limit under the combined action of the tube, shell side pressure and temperature difference load, forbidding considering the calculation result of nonexistent operation working condition; and if the primary stress is out of limit under the combined action of the tube and the shell side pressure, converting the secondary stress into the primary stress for controlling. The invention has the positive effect on making up the shortcomings because of adopting two calculation methods for designing flexible thin tube sheets for a long term, i.e. the defects of limited applicable range or long consumed calculation time, high calculation cost and complex calculation process. The method has wide applicable range, high calculation speed, simple calculation process and safe and reliable calculation result and conforms to the requirements of national energy saving and consumption reduction as well as cost saving for enterprises.

The invention provides a non-adhesion prestressing reinforcement material. A main stressed part comprises an internal reinforcement material and an outer layer reinforcement material; the internal reinforcement material is arranged inside the outer layer reinforcement material; the outer layer reinforcement material is made of polypropylene or polyvinyl chloride high molecular polymer; the internal reinforcement material is a high-elasticity modulus reinforcement material; and a lubricating agent is filled between the internal reinforcement material and the outer layer reinforcement material. According to the non-adhesion prestressing reinforcement material, the supporting effect of the reinforcement material on a soil body can be improved through the high-elasticity modulus reinforcement material in a tensioning inner layer. Therefore, the constraint of reinforcement belts on the soil body is increased, and the vertical deformation of filled earth is reduced; the non-adhesion prestressing reinforcement material can slide between the inner layer and an outer layer, so that the soil body cannot be driven to move towards the two sides in the tensioning process; and a composite material is formed by the outer layer reinforcement material and the soil body, so that the deformation of the soil body is further constrained. By mutually connecting a secondary stressed part with the main stressed part, the deformation of the soil body among the reinforcement belts on the same layer can be coordinated.