38 results about "Tangential stiffness" patented technology

The invention discloses a rough surface-based three-dimensional contact stiffness calculation method for a spur gear. The method comprises the steps of firstly by adopting hexahedral mesh generation, requiring all square meshes on a tooth surface to be equal in area; calculating contact pressure distribution of the smooth tooth surface based on a finite element method, and extracting node pressure intensity of a contact region; calculating normal contact stiffness and tangential contact stiffness of a single square mesh based on a fractal theory; and calculating the contact stiffness of the tooth surface. According to the method, the precision of a gear contact stiffness calculation model is further improved; the defect of smooth contact according to a Hertz theory in an original calculation process is overcome; an influence law of a roughness parameter on a gear stiffness characteristic in a rough tooth surface contact process and a calculation method are disclosed; and meanwhile, a finite element-based three-dimensional contact stiffness calculation model is more accurate than an original two-dimensional calculation model or calculation formula, and the influence of errors in actual assembling and manufacturing processes of the gear is considered, so that the gear contact stiffness is more accurate and a foundation is laid for gear dynamics analysis.

The invention discloses an automobile shock absorber and belongs to the field of automobiles. The automobile shock absorber is arranged inside an automobile steering wheel and comprises a mass block and a rubber column under the mass block, wherein the rubber column is used for supporting the mass block; and the mass block is fixedly connected with the rubber column, and the tangential inherent frequency of the automobile shock absorber is allowed to be close to the idle-speed vibration frequency of the automobile steering wheel so as to form resonance. The automobile shock absorber of the invention effectively utilizes the inner space of the steering wheel and the tangential stiffness property of rubber and adopts a shock absorbing structure comprising the mass block and the rubber column, so that a small-size and low-frequency power shock absorber is designed and manufactured, the idle-speed vibration problem of the steering wheel is solved, and the first application of shock absorber technology in solving the vibration problem of the idle-speed steering wheel in China is realized. Comparing with the prior art, the automobile shock absorber has the advantages of simple structure, simple and convenient processing and manufacturing, short development period, low cost and convenient popularization.

The invention discloses a dual-face locking knife handle-spindle system joint part stiffness characteristic optimization method based on particle swarm optimization. The dual-face locking knife handle-spindle system joint part stiffness characteristic optimization method based on particle swarm optimization adopts knife handle-spindle structural technological parameters and joint surface fractal parameters as optimization variables. The method comprises the steps that firstly, a three-dimensional fractal normal and shear stiffness model and a joint part torsion and radial stiffness model are built, and MATLAB programs are written separately; secondly, a contact-considering three-dimensional geometrical model is built for the dual-face locking knife handle-spindle system and static analysis is performed, so that an APDL file is obtained, and finally integration in Isight software and iterative optimization based on the particle swarm optimization are achieved. According to the method, the combination of the three-dimensional fractal micro contact stiffness modeling theory and finite element static analysis is adopted, the dual-face locking knife handle-spindle system joint part torsion and radial stiffness can be calculated under the high-speed condition, and the knife handle-spindle system optimization process on the Isight software platform based on the particle swarm optimization is achieved.

The invention provides an SH guided wave detection method for the interfacial state of a bonded structure. An expression containing a tangential rigidity coefficient K<T> for the reflection and transmission coefficients of a minimum-grade SH guided wave mode (SH<0>) in a plate-shaped bonded structure is deduced based on the governing equation of wave propagation. Taken an aluminum/epoxy resin/aluminum bonded structure as an example, the relation between incident angles and reflection or transmission characteristics of SH guided waves in different interfacial states is analyzed when the incident frequency f of the SH guided waves and the thickness h of a bonding layer are respectively set at specific values. Meanwhile, the influence of the product of frequency and thickness on reflection or transmission characteristics of the SH guided waves is discussed when the incident angles of the SH guided waves are set to be 0 DEG and 50 DEG C. How to discriminate interfacial states is also elaborated. Compared with other detection methods, the SH guided wave detection method for the interfacial state of the bonded structure has the advantages of easiness, effectiveness and practicability.

The invention relates to a device and a method for testing tangential rigidity of a junction surface of a wheel disc. The device comprises a universal testing machine, a pull rod rotor, a digital dial gauge I, a digital dial gauge II and a computer, wherein a pressure sensor arranged on the universal testing machine is connected with the computer by a data line; the universal testing machine further comprises a rack; an upper press head is arranged on the top of the rack; the digital dial gauge I and the digital dial gauge II are respectively positioned at two sides of the upper press head; a movable cross beam is arranged in the middle of the rack; two support blocks are arranged on the cross beam at an interval; the pull rod rotor is horizontally erected on the two support blocks; the pull rod rotor is positioned just under the upper press head. After the technical scheme is adopted, the technical problem that a device and a method which are used for testing the tangential rigidity of the junction surface of the wheel disc are lacked in the prior art can be solved.

The invention relates to a full-waveform information test method for the joint rigidity of rock mass. The method comprises data test and data analysis. The test comprises the following two steps: (1) testing the physical mechanics parameter of the rock mass within a test region, and (2) testing the normal rigidity and the tangential rigidity of the joint in the field; the data analysis comprises the following five steps: (1) building a time-domain analysis model when wavelet is propagated within the joint, (2) decomposing transmitted wave by the wavelet, (3) computing a wavelet system of incident wave and reflected wave, (4) computing time-domain wave form at an incident side which is in parallel with the joint trend and is vertical to the joint trend, and (5) computing the normal rigidity and the tangential rigidity of the joint. The test method is used for analyzing the rigidity of the joint based on the full-waveform information, a structural surface has the function of controlling the mechanical property of the rock mass, the exact acquisition of the normal rigidity and the tangential rigidity of the joint of the rock mass has important meaning on the design, the construction, the stability evaluation and the rock mass reinforcement of the rock mass engineering, According to the method, the operation is simple and quick, and the test cost is low, and a test result comprehensively reflects the complexity of the mechanical property.

The invention discloses a method for predicting interface failure and microscopic crack propagation of a composite material under a hydraulic osmotic load. The method comprises the following steps: representing a fracture state and interface distribution of a model by using a fracture phase field and an interface phase field; combining a phase field method and a Biot pore elastic medium theory inthe simulation and prediction process, calculating distribution of a displacement field and a liquid pressure field of the model under a hydraulic load, calculating the influence of the displacement field on the fracture phase field, and therefore achieving simulation of crack growth of a composite material under the mesoscopic scale when the composite material is subjected to the hydraulic load.According to the method, the interface normal rigidity and tangential rigidity are considered in a cohesion interface model. According to the phase field method model, the growth and bifurcation of the microscopic cracks of the composite material can be accurately simulated.

The invention discloses a joint rigidity analyzing method for a bi-side locking handle-main shaft under high rotating speed conditions, specifically to a joint portion rigidity modeling method taking non-uniform distribution of bi-joint-side pressure, and the system joint rigidity under high rotating speed conditions is analyzed based on the method. The method includes the steps of establishing a three-dimensional fractal normal and tangential rigidity model, analyzing to obtain pressure values of each node on a bi-joint side based on static force, calculating the equivalent rigidity value corresponding to the nodes, and obtaining the torsion and radial rigidity value through a confirmation model, and finally revealing the influence trend of broaching tool force, disk spring rigidity and disc spring pretightening force on the rigidity of the joint portion under different rotation speed and high rotation speed. The method is characterized in that the influence of elasto-plastic deformation and domain expansion factor are taken into consideration in the fractal theory, and nonuniformity of the pressure distribution on the joint surface is considered in the finite element analysis, thereby conducting accurate modeling and analyzing the joint rigidity of T40 handle-main shaft under high rotating speed conditions.

The invention discloses a method for judging the connecting compactness of an interface by using a spring stiffness coefficient. The method is mainly used for ultrasonic nondestructive testing of the interface compactness and comprises the following steps: (1) establishing a corresponding model according to actual conditions, and arranging a spring model at the interface; (2) deducing out a frequency dispersion equation of guided wave propagation according to a wave equation and boundary conditions; (3) drawing out a changing curve of phase velocity along with the tangential stiffness coefficient Kt under the condition that the normal stiffness coefficient Kn is infinitely great so as to obtain a tangential stiffness coefficient value with relatively sensitive phase-velocity change and a corresponding frequency-dispersion characteristic curve; (4) determining peeling-degree percentage values corresponding to different Kt values by simulation; (5) exciting and receiving ultrasonic guided wave signals on a tested object; (6) extracting parameters from actual testing signals to carry out inversion and further determine corresponding Kt values; and (7) judging the compactness degree of the interface by the tangential spring stiffness coefficient value. The method disclosed by the invention has the advantages that the connecting condition of the interface of a bonding part can be relatively well obtained and the quality monitoring and the maintenance can be carried out on the bonding part in a relatively effective manner.

The invention provides a method for calculating the tangential contact stiffness of a rough elastic interface, and belongs to the technical field of interface contact stiffness calculation. The methodcomprises the steps that firstly, an equivalent thin layer is used for replacing a rough contact interface, and elasticity modulus and shear modulus of a thin layer material are calculated; secondly,representing the contact stiffness of the rough elastic interface based on the modulus parameters of the thin-layer material, and deducing a specific value expression of the tangential contact stiffness and the normal contact stiffness of the rough elastic interface; obtaining the normal contact stiffness of the rough elastic interface according to the micro-contact deformation mechanism of the rough elastic interface; and finally, calculating the tangential contact stiffness of the rough elastic interface by combining the normal contact stiffness and the interface contact stiffness ratio expression. The invention provides the novel method for calculating the tangential contact stiffness of the rough elastic interface, the tangential contact stiffness characteristic of the rough elastic interface is disclosed, the calculation result is accurate, and a theoretical basis is provided for the tangential contact dynamics analysis of the rough elastic interface.

The invention provides a vibration damping support structure, a compressor and an air conditioner. The vibration damping support structure includes a support leg and a vibration damping pad, the support leg includes a flat plate with a hole and a reinforcing pipe, and the reinforcing pipe is arranged in the hole in a penetrating manner; and the reinforcing pipe is arranged in the vibration damping pad. The reinforcing pipe is arranged in the flat plate of the support leg in the penetrating manner, the contact area between the support leg and the vibration damping pad is increased, the radial or tangential stiffness is increased, greater force can be borne, the requirement for the large rigidity required by low frequency vibration is met, and the effects of reducing vibration and increasing the vibration isolation rate are achieved.

The invention relates to a method for calculating micro-mechanical parameters of reinforced tailings based on PFC discrete elements. The method comprises the following specific steps: obtaining macromechanical parameters through a geogrid and tailing sand indoor direct shear test; by utilizing PFC discrete element software, establishing a direct shear test numerical model, determining an overlying load by adjusting servo confining pressure in the model, and before the direct shear test of the model is started, substituting macro mechanical parameters such as peak shear stress intensity, density, apparent cohesive force, an internal friction angle and a friction coefficient calculated by the test into a command; and, after the program is started and the operation is completed, obtaining the numerical values of the normal stiffness and the tangential stiffness of the mesomechanics parameters in the model shear test process. The method has the advantages that: macroscopic mechanical parameters are obtained through indoor tests, mesoscopic mechanical parameters can be obtained through numerical simulation calculation, a macroscopic and mesoscopic parameter relevance calculation method is improved, calculation efficiency is higher, results are more accurate, important mesoscopic mechanical parameter indexes can be provided for safety and stability calculation of the reinforced tailing fill dam, and the contact state of the tailings particles is clearly described in numerical simulation, so that a numerical simulation result is closer to an actual working condition.

The invention relates to a method for acquiring the dynamic stiffness of a rock joint, and belongs to the technical field of rock mass measurement. The method comprises the following steps: preparing a rock sample containing the joint, carrying out a uniaxial compression test on the rock sample, and determining an equivalent normal stress sigma n and an equivalent tangential stress sigma t on a plane where the joint is located according to an applied compression external load sigma 0; shooting an image of the rock in the compression process, and determining a displacement field and a strain field in the rock test process according to the shot image; determining the thickness of the joint according to the strain field, selecting a plurality of characteristic sections in the length direction of the joint, determining displacements of upper and lower edge measuring points of the characteristic sections, and determining an average normal displacement un and an average tangential displacement ut on a plane where the joint is located; and determining the dynamic normal and tangential stiffness of the joint according to a joint stiffness calculation formula.

The invention belongs to the technical field of mechanical test devices, and provides a contact interface tangential rigidity testing device based on the cyclic load of a piezoelectric actuator. The invention provides a testing machine structure capable of testing the tangential rigidity of a contact interface under the cyclic load. According to the design, the piezoelectric actuator is used for applying a transverse load with a determined size, the generated transverse load is controlled by controlling the input voltage of the piezoelectric actuator, and an equal-size reverse transverse loadis input through the resilience force of a spring. Different from the prior art that only the tangential rigidity under static contact can be tested, the method can provide the cyclic load with a determined amplitude, and can feed back the dynamic tangential force of the contact interface through a force sensor and feed back the dynamic displacement of the contact interface through a laser displacement sensor so as to determine the dynamic tangential rigidity of the contact interface. In addition, test pieces of different sizes can be tested.