70 results about "Lateral shear" patented technology

The invention belongs to the technical field of tunnel construction, and discloses an upper-soft lower-hard composite stratum shield hob impact load determination method and system.The method comprises the steps that rock is divided into a plurality of concentric circle areas through a cavity expansion model, the radius of each area is determined, and the relation between the damage states of different positions of rock mass and the distance position of the center of a blade is obtained; the influence of section penetration is introduced, and based on the influence of the damage difference between a vertical crack area and a dense nuclear area in the hob rock breaking process, the damage state of the hob section away from the center of a blade within the range of a hob lower contact area and the damage distribution state of the hob lower hard rock side in the interface vertical crack expansion process are determined; and determining an expression of stress change of the transition section based on a CSM model, and realizing impact load prediction when the shield hob passes through the upper-soft and lower-hard composite stratum in combination with the influence of damage of the lateral shearing region. The damage effect and cavity expansion model theory is introduced for the first time, the compatibility of the prediction model and the actual situation is improved, and the abnormal damage rate of the hob is reduced.

The invention belongs to the technical field of mechanical test devices, and provides a multifunctional rock joint full-shear-seepage coupling test system comprising a heating module, the multifunctional rock joint full-shear-seepage coupling test system comprises a constant-temperature box, the constant-temperature box is internally provided with a confining pressure generating mechanism for injecting water into the constant-temperature box; the shearing assembly comprises an upper shearing box and a lower shearing box which are arranged in the constant-temperature box, the top and the bottom of the sample are clamped in the upper shearing box and the lower shearing box respectively, loading mechanisms are arranged between the upper shearing box and the constant-temperature box and between the lower shearing box and the constant-temperature box, and the loading mechanisms are used for enabling the upper shearing box and the lower shearing box to longitudinally clamp and transversely shear the sample; the high-temperature loading assembly is arranged in the constant-temperature box and is used for heating water in the constant-temperature box; a crack is formed in the middle of the sample, and the seepage assembly is used for enabling seepage water to flow through the crack of the sample to form crack seepage. According to the invention, comprehensive simulation of a'heat-force-water 'multi-field coupling environment where underground deep rock joints are located is realized in one system.

The invention relates to the technical field of building structures, and discloses a profile steel supporting structure which comprises a frame assembly, a supporting column and a reinforcing assembly. The frame assembly is parallel to the ground, the supporting column is perpendicular to the ground, the frame assembly is connected with the supporting column, and a strong shaft of the frame assembly is perpendicular to the ground. The reinforcing assembly is arranged in the direction of the minor axis of the supporting column, the reinforcing assembly is connected with the frame assembly and the supporting column and used for reinforcing the strength between the frame assembly and the supporting column, and the major axis of the frame assembly is perpendicular to the ground, so that the requirement for bearing capacity can be met, and the reinforcing assembly is connected to the frame assembly and the supporting column. Therefore, the overall lateral shearing force can be improved, the technical problem that in the prior art, the bearing capacity and the lateral shearing force are difficult to balance is solved, and the technical effect of meeting the bearing capacity and the lateral shearing force is achieved.

The application discloses a self-tapping and self-drilling screw connection strength simulation analysis method and relates to the technical field of simulation analysis.The application constructs a three-dimensional geometric entity of a screw and a base material, adopts explicit dynamics to complete dynamic simulation of a tapping process, extracts and reconstructs a thread interface deformation profile and a partitioned work hardening parameter, introduces tapping residual stress into a regular bearing grid through cross-stage inverse distance weighted stress mapping, combines partitioned equivalent contact stiffness and a friction coefficient to complete pre-tightening contact state initialization, carries out axial pulling-out and transverse shearing composite bearing simulation, judges a failure starting position and a final connection strength, and iteratively corrects simulation parameters through a strengthening correction factor based on measured pulling-out force data, effectively solves the problem that traditional simulation ignores tapping residual stress, interface deformation and work hardening effect, and leads to large strength prediction deviation, and significantly improves the prediction precision and engineering applicability of self-tapping and self-drilling screw connection strength simulation.

The utility model relates to a transverse impedance multidirectional damping steel spring device which comprises a spring outer sleeve (1), a steel spring (5) and a spring inner sleeve, the spring inner sleeve comprises a spring inner sleeve cover (2) and a spring inner sleeve base (6), and a transverse impedance elastic body (3) for transverse limiting is arranged between the spring outer sleeve (1) and the spring inner sleeve base (6). Compared with the prior art, three-direction damping amplification is adopted, besides the main vibration isolation direction, the stability and vibration in the direction perpendicular to the main vibration isolation direction of the spring can be controlled, and meanwhile the problem that the spring is subjected to transverse shearing dynamic load to cause fatigue fracture and failure of the spring is solved; therefore, the transverse stability and reliability are improved, and the service life of parts is prolonged.

An automatic overturning device for fabricated prefabricated components, comprising a chassis, a sliding support, a track, an anti-overturning vertical rod, an anti-overturning horizontal rod, a detachable supporting base, a magnetic rubber pad, an overturning frame, a hydraulic cylinder and a hydraulic control system. The device has the following effects: the prefabricated component can be hoisted and laid flat on the sliding support by a crane, the hydraulic system can overturn the overturning frame and the prefabricated component to a position with an angle of 0-90 degrees with the horizontal plane. The overturning process does not need to cooperate with the operation of the overhead crane through a steel wire rope, and the work efficiency is greatly increased. The magnetic rubber pad can protect the bottom of the prefabricated component in the process, but it is not used as the fulcrum of overturning, so the overall prefabricated component will not be damaged in the overturning process. The lifting ring at the top of the prefabricated component does not participate in the overturning process, and will not be deformed due to lateral shear force, so the structural integrity of the prefabricated component and the safety of subsequent hoisting are reliably guaranteed.

The invention discloses a ballastless track turnout fastener system and a ballastless track, and relates to the technical field of railway construction, the ballastless track turnout fastener system comprises a base plate, a first buffer base plate, a second buffer base plate, a first height adjusting base plate, a force transmission sleeve, a switch tie bolt and a positioning mechanism. The first buffering base plate, the base plate, the second buffering base plate and the first height adjusting base plate are sequentially arranged in a stacked mode. The force transmission sleeve penetrates through the base plate and the second buffering base plate at the same time and makes contact with the first height adjusting base plate. The switch tie bolt is arranged in the force transmission sleeve in a penetrating mode and penetrates through the first height adjusting base plate. The positioning mechanism is fixed to the base plate and used for positioning the steel rail body. The risk that the switch tie bolt is damaged due to transverse shearing force can be reduced, safety is improved, and maintenance cost is reduced.

The utility model relates to the field of concrete tower drums, in particular to a tower drum duct piece vertical seam connecting structure which comprises a duct piece and a connecting assembly, the two ends of the duct piece are fixedly connected with a first blocking strip and a second blocking strip respectively, the two ends of the duct piece are provided with a first inserting groove and a second inserting groove respectively, and the two ends of the duct piece are provided with reinforcing grooves respectively. Reinforcing assemblies used for assisting connection of the adjacent pipe pieces are arranged in the reinforcing grooves. The first barrier strip and the second barrier strip are arranged in a matched mode, double-bending blocking is formed on the segment splicing face, transverse shearing force is effectively dispersed, the segments are prevented from dislocation or sliding under the action of external force, the overall structural stability of the tower drum is further enhanced through the application of the reinforcing grooves and the reinforcing assemblies, and the service life of the tower drum is prolonged. The bearing capacity and the reliability of the wind power tower cylinder when the wind power tower cylinder bears external force are effectively improved, and the risk that the grouting material falls off or the bolts loosen due to external force loads is reduced.

The invention discloses an inertial yaw damping technology which relates to the fields of construction, manufacturing, traffic and the like related to the damage of the transverse action of earthquake vibration waves and is used for blocking the transverse action of the vibration waves from being conducted to a construction structure body with the mass inertia characteristic by utilizing resistance through a resistance reducing and resisting method. The vibration wave conduction bearing body and the building structure body are separated through the yaw balance bearing device, free, low-resistance, full-width, omnidirectional, balanced, stable and controllable full yaw bearing of the yaw balance bearing device during an earthquake is used for resolving and eliminating transverse shear damage of vibration waves to the building structure body, and the purpose of maintaining the building structure body not to be damaged by a large earthquake is achieved.

A battery pack includes two lid modules and at least one battery module (3010) including battery cells (0020), a cell holder (0050), and a liquid-limiting casing (0080). The liquid-limiting casing (0080) is a tubing structure having a peripheral wall (0090) laterally surrounding a battery-pack space (3032) and having a mechanical interlocking structure on a vertical end of the liquid-limiting casing (0080). The lid module includes a lid interlocking structure mechanically engaged with the mechanical interlocking structure. The peripheral wall (0090) includes a sealing-member-accommodating structure (0220). The battery pack further includes a sealing member (0200) accommodated in the sealing-member-accommodating structure (0220). The lid module has a lid-sealing surface compressing the sealing member (0200). The mechanical engagement between the mechanical and lid interlocking structures restricts a relative lateral displacement between the lid module and the liquid-limiting casing (0080), thereby maintaining a compression status of the sealing member (0200) against lateral shear forces.

Disclosed embodiments provide light-emitting diodes (LEDs) and interconnect structures that employ particularly shaped electrodes and a conductive metal-based adhesive that are selected to provide a flexible, robust interconnect that is capable of resisting lateral shear forces, while maintaining a low bond process temperature that is process compatible with other LED component materials. In a non-limiting aspect, disclosed embodiments employ a barrier coating on the interconnect or bonding materials comprising a conductive metal-based adhesive to inhibit moisture and air contact with the conductive metal-based adhesive, thereby preventing or mitigating migration of metal ions in the conductive metal-based adhesive in operation.

The utility model discloses a CFG drilling machine device for square pile construction, and belongs to the technical field of foundation treatment. The device comprises a drilling assembly, the drilling assembly comprises a spiral drill rod and a drill bit which are connected, the outer wall of the spiral drill rod is provided with drill rod spiral blades, the drill rod spiral blades extend outwards to form a plurality of blade protruding parts arranged at equal intervals, and the drill rod spiral blades are in a triangle-like shape on the vertical projection plane; the square pile limiter is provided with a square limiting hole; the spiral drill rod penetrates through the limiting hole, and the blade protruding part of the drill rod spiral blade abuts against the inner wall of the limiting hole. And the rotary driving mechanism is connected with the spiral drill rod. Under the condition of the same bearing capacity, the length of the pile body can be reduced, and the construction cost is saved. According to the construction mode, the square pile is in a square shape, large impact resistance is achieved, more materials are distributed at the corners of the square pile, and lateral shearing force and torque effects can be better resisted.

A system may include a lateral shearing interferometer. The lateral shearing interferometer may enable measuring a surface profile of a sample, such as the pattern wafers, using reflected light from the sample. The reflected light may be reflected at a grazing incidence angle. A controller may receive images from the lateral shearing interferometer and measure the surface profile. The controller may measure the surface profile by reconstructing a phase of the reflected light from the images. The controller may reconstruct the phase using spatial reconstruction or time-domain reconstruction. The gratings may allow the controller to measure the edge roll-off in one or two dimensions. The controller may also calibrate the grazing incidence angle and determine refractive indices of thin-films on the sample. The controller may also perform full measurements of the surface profile using line beams, rectangular beams, or full-sample beams.

This application discloses a pump tower and a fluid storage tank, including a storage tank insulation module. The pump tower includes a pump tower base, a guiding device, a connecting support rod, and a base plate. The pump tower also includes an anti-tilting support frame. This application provides several outwardly extending anti-tilting support frames on the outer wall of the pump tower base, and the anti-tilting support frames are plugged into the guiding device. When the pump tower generates tilting moment or lateral shear force due to ship swaying or internal fluid impact, the curved surface of the anti-tilting support frame can physically limit and support the guiding device, preventing irregular displacement of the guiding device and the base plate. This application disperses the multi-directional stress at the bottom of the pump tower, improving the anti-tilting capability and service life of the storage tank pump tower structure under complex dynamic load environments. It also discloses a fluid storage tank including a pump tower, which improves the anti-tilting capability and overall operational safety of internal equipment under complex dynamic loads and fluid impacts, and extends the service life of the storage tank system.

The utility model relates to the technical field of building construction devices, in particular to an adjustable anti-seismic reinforcing plate for building construction. Comprising a supporting plate and a bottom plate, a main supporting column is fixed to the bottom plate, a rotatable main steering ball head is arranged at the top of the main supporting column, and the main steering ball head is fixedly connected with the back face of the supporting plate through a connecting column; rotating blocks penetrating through the supporting plate front and back are arranged on the two sides of the upper end of the supporting plate correspondingly; the supporting plate is in an L shape, the front end of the supporting plate is fixedly connected with the friction bottom plate, the friction plate is fixed to the front end of the friction bottom plate, the supporting plate is in sliding connection with the friction abutting plate at the front end of the friction plate through a groove in the bottom, and side plates for preventing the friction abutting plate from falling off are installed on the left side, the right side and the top of the supporting plate. The inclined direction of the supporting plate can be changed by adjusting the fixing block and the main steering ball head, then an inclined object is reinforced, and meanwhile energy absorption can be carried out on longitudinal vibration and lateral shearing force vibration so as to achieve the purposes of buffering and shock absorption.

The invention relates to the technical field of composite bars, in particular to a steel-FRP composite bar and a preparation method thereof.The steel-FRP composite bar comprises a three-section structure including an outer layer, a middle layer and an inner layer; the outer layer is formed by compounding high-modulus alkali-free glass fibers and fluorocarbon resin; the middle layer is formed by matching high-modulus alkali-free glass fibers with epoxy resin; and the inner layer is doped with elastomer particle modified resin. The winding structure with the gradually-changed fiber angle is developed, the winding angle of the glass fiber is gradually transited from 90 degrees (longitudinal reinforcement) to 30 degrees (circumferential reinforcement) from the inner layer to the outer layer, the composite rib can meet the requirements for high axial tensile strength and transverse shear resistance at the same time, and the composite rib is suitable for complex stress scenes such as bridge bearing.

The invention discloses an angle ring slitting device capable of achieving multilateral shearing and a working method thereof, and belongs to the technical field of electrical equipment insulation part machining. The device comprises a rack, a double-shaft linkage shearing knife set, an arc-shaped guiding system and a radian adjusting mechanism; the double-shaft linkage shear knife set is composed of two sets of independent shear units coordinated by a control system, the blade axes of the two sets of independent shear units are perpendicular to each other, and synchronous shear of transverse edges and vertical edges is achieved. The arc-shaped guide system and a bearing form a spatial arc-shaped supporting surface through a plurality of groups of guide rods, and the spatial arc-shaped supporting surface is used for accurately positioning and guiding an angle ring blank; the radian adjusting mechanism drives a gear-arc-shaped rack pair through a motor to drive the vertical edge shearing unit and part of the guide assemblies to move along an arc-shaped track, and self-adaption to angle rings with different curvatures is achieved. According to the invention, multiple procedures are integrated into single-procedure synchronous shearing, so that the processing efficiency, precision and automation level are remarkably improved, and the device is suitable for batch precision production of the sectioning angle rings of the transformer.

This invention provides a shear wave impact pad and operating method for shallow seismic exploration, comprising a load-bearing block, a wedge, and two symmetrically arranged inclined plates. The load-bearing block is connected to the wedge, which is positioned between the two inclined plates, with its sidewall slidingly engaged with the inner wall of the inclined plate. When the load-bearing block is subjected to a vertical impact force, the wedge moves downward and pushes the two inclined plates symmetrically outward along the sliding engagement surface, thereby converting the vertical impact force into a lateral shear force. This invention uses the load-bearing block, wedge, and symmetrically arranged inclined plates to form a linkage and reversing structure for converting vertical force into lateral force. Vertical impact drives the wedge downward, simultaneously pushing the two inclined plates symmetrically outward to generate bidirectional equal-intensity shear waves, replacing the traditional side-impact plate operation method, improving shear wave conversion efficiency, and enabling shear wave excitation with minimal source-receiver distance, thus meeting the operational requirements of shallow seismic exploration.

The utility model provides a shock absorption device for tunnel blasting construction, relates to the technical field of tunnel construction, and aims to solve the problems that when blasting operation is implemented, an existing shock absorption device mostly focuses on buffering and reducing impact energy transmitted from a soil layer, and the shock absorption effect is poor. However, the process that blasting impact force is conducted to a conduction vertical rod of a damping device by means of an air medium is neglected, in the process, the impact force easily derives lateral shearing force on the surface of the conduction vertical rod, and along with increase of blasting frequency and accumulation of impact energy, the conduction vertical rod bears the lateral shearing effect for a long time, so that the structure is easily damaged; the damping device comprises a main body, and the service life of the damping device is shortened. When the conduction rod is subjected to lateral shear force generated by blasting, the lifting frame deflects to push the buffer plate, and the buffer plate buffers by means of the elastic piece, so that lateral shock absorption of the conduction rod is achieved, the conduction rod is effectively protected from being damaged by the lateral shear force, the overall service life of the shock absorption device is prolonged, and long-term stable operation of the shock absorption device is guaranteed.

The invention discloses a full-polarization birefringence interference hyperspectral imaging device and method based on a Savart cutter. The device comprises a front imaging objective lens, a diaphragm, a collimator objective lens, a polarization modulation system based on ferroelectric liquid crystal, a birefringence shearing system, a rear imaging objective lens and a detector which are sequentially arranged in the direction of an optical path. The method comprises the following steps: incident light enters the polarization modulation system based on the ferroelectric liquid crystal in the form of a collimated light beam after passing through the front imaging objective lens, the diaphragm and the collimator objective lens; the light beam subjected to polarization modulation enters a birefringence shearing system; transverse shearing is generated through the birefringence shearing system; the double beams after transverse shearing are incident to a rear imaging objective lens and are imaged on a target surface of a detector to form a polarization interference image; and processing the polarization interference light intensity information obtained on the target surface of the detector to obtain spectral information and full polarization information of each point of the target. Spectral information and full polarization information can be obtained at the same time, polarization state information can be obtained with high precision, and broadband adaptability is achieved.

The utility model relates to the field of airplane body structures, and provides an empennage and fuselage connecting structure and an airplane, the connecting structure comprises a first empennage connecting rib, a second empennage connecting rib, a fuselage connecting rib, a fuselage connecting corner box and a reinforcing band plate; each group of first empennage connecting ribs and each group of second empennage connecting ribs enclose a closed curve for accommodating an empennage box section; the fuselage connecting rib is used for fixedly connecting the first and second empennage connecting ribs respectively; one end of the fuselage connecting rib is fixed on the fuselage connecting corner box; the reinforcing band plates are arranged on the upper portions and the lower portions of the first empennage connecting ribs and the second empennage connecting ribs and fixed to the fuselage connecting ribs. And the fuselage connecting corner box is fixedly connected to the fuselage tail frame. The connecting structure is of a box-shaped structure and has large course torsional rigidity; stress concentration at the joint is reduced based on an empennage skin dispersed load transfer mode; the fuselage connecting rib edge strips, the fuselage connecting corner boxes and the connecting band plates form a shear-resistant structure, and the lateral shear rigidity is large; the structure is simple and installation is convenient.

The present invention discloses a deformation-coordinated connection method for a ship lift tower and an elevated navigable aqueduct. The method includes providing a sliding hinge support and a water-stop structure at the connection between the ship lift tower and the elevated navigable aqueduct; determining the sliding friction coefficient μ of the sliding hinge support so that the sliding hinge support does not move under wind loads and small earthquake loads; determining the width L of the water-stop structure along the water flow direction of the elevated navigable aqueduct so that the water-stop structure is not damaged under wind loads and small earthquake loads; and determining the maximum allowable lateral sliding displacement d of the sliding hinge support at the connection under moderate earthquake loads. m The invention prevents the sliding hinge support from being damaged under moderate earthquake loads. The invention also determines the minimum shear force F that would damage the sliding hinge support, ensuring that the sliding hinge support is damaged under large earthquake loads, thereby preventing damage to the elevated navigable aqueduct. The invention prevents the navigable aqueduct from being damaged and causing safety accidents due to large lateral shear forces.

This invention provides a chain hook traction device testing system and method, relating to the field of traction testing systems. Addressing the problem of existing testing machines' difficulty in real-time and accurate monitoring of chain hooks and traction devices during loading tests, a gantry loading frame is installed on a base. Two sets of actuators are installed side-by-side on the lower part of its crossbeam, corresponding to the chain hook testing station and the traction device testing station, respectively. A self-aligning connection component is provided between the actuator and the test piece. This component, utilizing its structural characteristics, can automatically adjust the force axis during loading, thereby effectively improving or eliminating the lateral shear force on the test piece. Non-contact real-time image data acquisition is performed using visual monitoring devices arranged around the testing stations and transmitted to the control console, achieving continuous and safe monitoring of crack initiation and propagation processes. This effectively meets the EN15566 standard's requirements for real-time, accurate, and safe testing under high dynamic loading environments.

A connecting plate for a derrick cross beam of a carrier cable crossing system is characterized in that the derrick cross beam and connecting plates vertically arranged at the two ends of the derrick cross beam are arranged, the connecting plates are fixedly connected with the derrick cross beam through matched connecting bolts, and construction holes are symmetrically formed in the upper portions and the lower portions of the connecting plates; a U-shaped ring lock is arranged in the upper construction hole, and a suspension rope is suspended in the U-shaped ring lock; a U-shaped ring lock is arranged in the lower construction hole, and a bearing cable pulley is hung, so that the situation that the hanging rope and the bearing cable pulley directly act on the derrick cross beam at the same time, transverse shearing force exists on the derrick cross beam, and potential safety hazards are generated can be avoided.

The present invention relates to the field of automobile technology, and specifically to an automobile engine compartment connection structure, comprising a loading adapter assembly, wherein an axial adapter assembly is provided on the loading adapter assembly, and the first and second reinforcing adapter plates are provided to ensure high connection stability between the upper loading plate and the lower loading plate and the first and second loading seats, and the lateral shear force of the loading adapter assembly can be buffered and reduced by the spring column, so that the installation stability of the engine compartment is high, and the mounting seat is fixedly connected to the bottom of the upper loading plate and the positioning column is fixedly connected to the end of the lower loading plate, so that the transfer effect of the axial adapter assembly and the loading adapter assembly can be improved, and the axial adapter assembly can convert the lateral shear force on the loading adapter assembly into a vertical axial force, so that the stability and safety of the use of the loading adapter assembly can be high, thereby improving the stability and safety of the use and installation of the automobile engine compartment.

The application relates to the technical field of composite bars, in particular to a steel-FRP composite bar and a preparation method thereof, which comprises a three-section structure of an outer layer, a middle layer and an inner layer; the outer layer is composed of high-modulus alkali-free glass fibers and fluorocarbon resin; the middle layer is composed of high-modulus alkali-free glass fibers and epoxy resin; and the inner layer is composed of modified resin mixed with elastomer particles. The application develops a winding structure with gradually changed fiber angles, and the winding angle of the glass fibers gradually changes from 90 DEG (longitudinal reinforcement) to 30 DEG (circumferential reinforcement) from the inner layer to the outer layer, so that the composite bar can meet the requirements of high axial tensile resistance and transverse shear resistance, and is suitable for complex stress scenes such as bridge bearing.

The invention relates to the technical field of preparation of layered products, and discloses a PVDF (polyvinylidene fluoride) film and metal substrate high-temperature melting and laminating process which comprises the following steps: preheating a metal substrate to enable the surface temperature of the metal substrate to be above the melting point of a film material, guiding the normal-temperature film material to cut into a nip point of a pressing and laminating roller at a tiny offset included angle to form a transverse exhaust wave, a transverse shear field is introduced on an interface by adjusting the speed ratio of a pressing roller to the substrate, melt is driven to fill micropores in the surface of the substrate, and the speed ratio is adjusted according to motor current load deviation; keeping the complex at a constant temperature near the crystallization temperature to induce in-situ relaxation of an interface chain segment; according to the method, the apparent viscosity of the melt is reduced by utilizing an interface shear field, a microporous air plug is eliminated, and a crystallization buffer layer with modulus in gradient distribution is constructed between heterogeneous materials, so that essential transformation from discrete physical stacking to a continuous microscopic mutual embedding structure is realized, and the interface bonding strength consistency and the cold-bending-resistant processing performance are improved.

The utility model belongs to the technical field of fire-fighting tools, disclose a carbon fiber material's fire-fighting extension ladder, including a plurality of rungs of telescopic cooperation of mutual laminating, the rung includes one fixedly installed bottom rung and at least one relatively pullable pull rung, is equipped with self -locking mechanism between adjacent rungs, both sides of each rung are equipped with side rod, and side rod is set to carbon fiber section bar integrated hollow pole body, and the top of side rod is equipped with the upper convex slide way that protrudes outward along the length direction of side rod. The utility model discloses the lateral guide wheel of the inside cooperation of being equipped with side slide groove and it forms rigid lateral restraint, effectively resists the lateral shearing force between rungs, significantly improves the bending and torsional stiffness of whole ladder stand, prevents the shaking, distortion or instability deformation of ladder in use because of lateral force, greatly improves the security and structural stability, and simultaneously, because of reliable constraint, reduces the fretting of rung connecting place, prolongs the service life.

An energy return device for a midsole of a shoe comprises a resilient foam or matrix structure, such as a domed disk, around a cavity. The resilient structure is arranged to collapse into the cavity under foot strike pressure. The structure may initially resist the pressure primarily by compression forces directed around the cavity. As the cavity collapses these forces may provide decreasing vertical spring rate as the structure bends or as the forces become less vertical, causing the structure to stay more compressed through the midstride and energy return to be delayed until the user has moved further forward in their stance. At full collapse the material of the structure may resist further downward force of the user by direct compression. A lateral expansion limiter may resist lateral expansion to increase vertical force supplied by the compression forces around the cavity and reduce interference with other components.