An elastic matrix determination method and a vibration analysis method for a laminated iron core, with which it is possible to optimally determine an elastic modulus of a laminated iron core. When a vibration analysis of a laminated iron core obtained by laminating steel sheets is performed by using a configuration expression indicating a relationship between stress and strain in a matrix display by using an elastic matrix, a shear modulus in two surfaces including a laminating direction of the laminated iron core included in the elastic matrix in the configuration expression is determined in consideration of slip between laminated steel sheets.

A method and system for calculating a primary shear zone stored energy field during steady-state cutting, the method including: fitting parameters of a workpiece material stored energy evolution model; discretizing the primary shear zone into infinitesimals on a main shear plane. The infinitesimals are small enough, a strain, strain rate, and temperature are assumed constant; introducing an equivalent cutting edge model simplifying three-dimensional cutting into two-dimensional cutting, calculating element strain and strain rate using a shear plane model, and analyzing element temperature using a heat conduction equation; deriving a differential equation of stored energy versus location in the primary shear zone using stored energy evolution, strain rate distribution, strain distribution, and temperature distribution models; and solving the differential equation for each infinitesimal using an initial shear plane as a model boundary, obtaining stored energy at each location to obtain a stored energy field distribution of the primary shear zone.

Method for simulating chatter-free milled surface topography includes: performing dynamics modeling on milling system and building delay differential equation with multiple delays to represent dynamic model; constructing state transition matrix between two adjacent cutting tool rotation periods by extending GRK method; predicting stable milling parameter zones based on Floquet theory; calculating vibration displacements on discretized time nodes during one cutting tool rotation period by means of fixed mapping point theorem; constructing motion trajectories of cutting tool edges in normal and feed directions with regard to milled surface of workpiece; predicting surface topography of workpiece by using spline interpolation to densify motion trajectories of cutting tool edges that participate in generating final surface of workpiece; calculating surface location error of milled surface based on motion trajectories of cutting tool edges in normal direction with regard to milled surface of workpiece; calculating surface roughness based on the simulated surface topography of workpiece.

The invention discloses a mechanics calculation method of drill bit tooth considering rock dynamic strength and mixed crushing mode, including: Step S1: selecting a target drill bit tooth and a target rock, and determining a type of target drill bit tooth, a geometry of the target drill bit tooth, a rock type and rock parameters of the target rock; Step S2: calculating a horizontal cutting force of the target drill bit tooth according to a horizontal cutting mechanics calculation method of drill bit tooth; Step S3: calculating a vertical penetration force of the target drill bit tooth according to a vertical penetration mechanics calculation method of drill bit tooth; Step S4: calculating a resultant force experienced by the target drill bit tooth according to a resultant force calculation method of drill bit tooth. The invention provides a calculation method for accurately obtaining drill bit tooth mechanics under different working conditions.

The invention discloses a drill bit design method based on rock crushing principle with local variable strength, including: drill bit is divided into local crushing feature regions; strength mode factors of the local crushing feature regions are calculated; a difference among strength mode factors of the local crushing feature regions is obtained to obtain a vector sum of horizontal cutting forces of the drill bit tooth corresponding to the same group of cutting tooth on the drill bit; treating the difference among the strength mode factors of the local crushing feature region as a target control condition for drill bit design. Based on the rock crushing principle with local variable strength, after dividing the symmetrical cutting tooth into groups, the strength variation factors of the symmetrical position are adjusted and balanced, so that the rock crushing strength of different local crushing feature regions can be changed in a targeted manner.

A program according to one aspect of the present disclosure relates to a program executed by a computer including a processor, the program causing the processor to perform: obtaining specification data indicative of a specification required for at least one of a functionality and a performance of a to-be-designed three-dimensional structure; and determining a candidate structure based on the required specification from a database, wherein a parameter describing a physical property of respective candidate structures that differ from each other in terms of at least one of a material and a structure is registered in the database.

Disclosed are a method using a sequential contact analysis of a nano-asperity in order to predict an adhesion force between two contacting surfaces and a recording medium recording a program. According to an exemplary embodiment, the method may include: receiving surface roughness data of each of the two target objects; modeling a rough surface based on the surface roughness data; computing an adhesion force value when the two target objects contact and a deformation value of the first nano-asperity; determining whether a next contact is established; iteratively performing the computing and the determining when the deformation value of the first nano-asperity is larger than the separation distance of the next nano-asperity; and determining that a next contact is not established and computing and outputting force adhesion force in a final contact situation, when the deformation value of the first nano-asperity is smaller than the separation distance of the next nano-asperity.

To accurately estimate frequency characteristics from structural parameters of a frequency selective surface. A frequency selective surface design apparatus includes an LC generation unit 20 that receives an input of a structural parameter, and generates an inductance L and a capacitance C of a unit cell, a corrected resonance point calculation unit 30 that receives the number n of times of calculation input from an outside, the inductance L, and the capacitance C, models a correction circuit by using a circuit in which a virtual capacitance is connected in parallel via a transmission line to each distribution inductance obtained by division of the inductance L by the calculation number n and the transmission line is terminated at the capacitance C, and calculates a corrected resonant frequency fC from the impedance of the correction circuit, and a characteristic calculation unit 40 that receives inputs of the inductance L, the capacitance C, and the corrected resonant frequency fC, calculates a pre-correction resonant frequency from the inductance L and the capacitance C, obtains a correction coefficient by dividing the corrected resonant frequency fC by the pre-correction resonant frequency, and calculates a corrected return loss and a corrected insertion loss.

Methods, systems, and apparatus, including medium-encoded computer program products, for computer aided design of physical structures using generative design processes include: obtaining one or more design criteria, a model of an object for which a physical structure is to be manufactured, and a set of eigenmodes from a modal analysis of the model of the object; extracting a proper subset of non-zero eigenmodes from the set of eigenmodes, wherein the proper subset of non-zero eigenmodes include at least three lowest valued, non-zero eigenmodes; combining data of the proper subset of non-zero eigenmodes to form a strain energy field for the model of the object; iteratively modifying a generatively designed shape of the model of the object using the strain energy field to drive changes to the generatively designed shape of the model; and providing the generatively designed shape of the model of the object.

The present invention discloses a multiaxial creep-fatigue prediction method based on ABAQUS, which comprises: S1: establishing an ABAQUS finite element model, and defining the viscoplastic constitutive equation of the material to be tested by means of the user subroutine UMAT; S2: determining the model parameters required by the viscoplastic constitutive equation; S3: establishing the fatigue damage calculation model and creep damage calculation model of the multiaxial stress-strain state of the material to be tested; S4: establishing an ABAQUS finite element model under the multiaxial stress-strain state, and calculating the stress-strain tensor of each cycle based on the defined viscoplastic constitutive equation and the model parameters; S5: calculating the equivalent stress and equivalent plastic strain by means of the user subroutine USDFLD, and superimposing the fatigue damage and creep damage of each cycle according to the linear cumulative damage criterion to obtain the crack initiation life of the material to be tested based on the fatigue damage calculation model and creep damage calculation model in combination with the stress-strain tensor.