CN-121997750-A - Copper male surface morphology data acquisition and analysis method for nickel sheet convex hull stamping

CN121997750ACN 121997750 ACN121997750 ACN 121997750ACN-121997750-A

Abstract

The application provides a copper male surface morphology data acquisition and analysis method for nickel sheet convex hull stamping, which comprises the steps of obtaining initial geometric parameters and material flow characteristic data of a nickel sheet, analyzing bidirectional tensile stress concentration degree of a bottom round corner region through stress distribution when the height of the convex hull is increased to obtain a strain concentration index of the bottom round corner region, determining round corner radius configuration corresponding to a deformation stage through a genetic algorithm according to the strain concentration index of the bottom round corner region, extracting metal transfer rate of a flange region from the corrected round corner radius configuration, simulating material flow balance of the flange region to the convex hull region, determining a predicted value of the bottom thinning degree of the convex hull, and evaluating risk of micro cracks along grain boundaries to initiate and expand according to optimized punch stroke parameters to generate a dynamic stamping control sequence.

Inventors

ZHANG XINSHU
HUANG SHENGFENG

Assignees

惠州市精工精金属制品有限公司

Dates

Publication Date: 20260508
Application Date: 20260128

Claims (10)

1. The method for collecting and analyzing the copper male surface morphology data for the nickel sheet convex hull stamping is characterized by comprising the following steps of: The method comprises the steps of obtaining initial geometric parameters of nickel sheets and material flow characteristic data, analyzing the bidirectional tensile stress concentration degree of a bottom fillet region through stress distribution when the height of a convex hull is increased to obtain a strain concentration index of the bottom fillet region, determining fillet radius configuration corresponding to a deformation stage through a genetic algorithm according to the strain concentration index of the bottom fillet region, judging whether points exceeding the uniform extension limit of materials exist in the fillet radius configuration, if so, obtaining modified fillet radius configuration through iterative adjustment genetic algorithm parameters, if not, directly entering the next material flow optimization analysis, extracting metal transfer rate of a flange region from the modified fillet radius configuration, simulating the material flow balance of the flange region to the convex hull region, determining a predicted value of the bottom thinning degree of the convex hull, relating the punch stroke and the fillet radius according to the predicted value of the bottom thinning degree of the convex hull, judging whether the requirement of the high convexity is met or not, circularly executing a particle swarm optimization algorithm to obtain optimized punch stroke parameters, and evaluating the risk of micro-crack initiation and propagation along a grain boundary according to the optimized punch stroke parameters, and generating a dynamic punching control sequence.
2. The method for acquiring and analyzing the data of the surface morphology of the copper core for the convex hull stamping of the nickel sheet according to claim 1, wherein the method for acquiring the data of the initial geometric parameters and the material flow characteristics of the nickel sheet, analyzing the bidirectional tensile stress concentration degree of the bottom fillet region through the stress distribution when the height of the convex hull is increased, and obtaining the strain concentration index of the bottom fillet region comprises the following steps: And performing gridding scanning on the nickel sheet to obtain a sheet thickness distribution cloud picture, collecting grain boundary distribution characteristics, capturing a deformation gradient field during convex hull forming in the process of gradually increasing the stamping speed, calculating stress tensor components of each grid node, judging the plastic deformation degree of a bottom fillet area, and calculating a strain concentration index of the bottom fillet area aiming at the area where the plastic deformation degree exceeds a threshold value.
3. The method for collecting and analyzing the copper male surface morphology data for the convex hull stamping of the nickel sheet according to claim 1, wherein the determining the fillet radius configuration corresponding to the deformation stage by a genetic algorithm according to the strain concentration index of the bottom fillet region comprises the following steps: Constructing an adaptation function according to the strain concentration index, wherein the adaptation function is a weighted combination of the fillet radius and the strain distribution uniformity, carrying out chromosome expression on the fillet radius in different deformation stages in a binary coding mode, screening good individuals by adopting a roulette selection operator, carrying out single-point cross operation and random disturbance variation on the good individuals, storing each generation of the highest-adaptability individuals, calculating individual fitness values, judging whether the fitness values exceed a target threshold value and the fillet radius is in an allowable range, outputting a fillet radius configuration sequence corresponding to the optimal individuals if the condition is met, and adjusting the selection pressure coefficient to continue iterative evolution until the fillet radius configuration meeting the constraint condition is obtained if the condition is not met.
4. The method for acquiring and analyzing the copper male surface morphology data for stamping the nickel sheet convex hull is characterized by determining fillet radius configuration corresponding to a deformation stage through a genetic algorithm according to strain concentration indexes of a bottom fillet region, comprising the steps of determining safe strain boundaries under different convex hull heights according to the strain concentration indexes of the bottom fillet region, dividing the safe strain boundaries into a plurality of deformation stage sections, identifying strain mutation points according to strain characteristics of each deformation stage section, setting fillet radius transition buffer areas before and after the mutation points, performing discretization processing on a strain tolerance range to calculate a strain gradient, constructing a cubic spline interpolation function in the transition buffer areas, enabling first derivatives of the interpolation function at the starting point and the end point of the buffer areas to be continuous, calculating fillet radius values corresponding to each discrete point in the buffer areas according to the interpolation function, adopting gradual adjustment to realize smooth transition of the fillet radius, combining critical strain values of each deformation stage, and recording the fillet radius values corresponding to each convex hull height and the applicable strain ranges of the complete fillet radius configuration table.
5. The method for collecting and analyzing the copper male surface morphology data for the nickel sheet convex hull stamping according to claim 1, wherein the method is characterized in that whether a point exceeding the uniform extension limit of a material exists in the fillet radius configuration is judged, if so, the modified fillet radius configuration is obtained by iteratively adjusting genetic algorithm parameters, and if not, the method directly enters the next material flow optimization analysis, and comprises the following steps: The method comprises the steps of extracting strain values from round angle radius configuration point by point, comparing the strain values with the material uniform extension limit, marking the points as default points if the strain value of a certain point exceeds the limit value, calculating the excess quantity of each default point, determining the correction amplitude according to the maximum value of the excess quantity, adjusting the crossover probability and the variation probability of a genetic algorithm to carry out iterative optimization, judging the default points again after each iteration, expanding the value range of the round angle radius to execute the genetic algorithm again if the default points still exist after the preset iteration times, and otherwise, directly using the current round angle radius configuration for material flow optimization analysis.
6. The method for collecting and analyzing the data of the surface morphology of the copper core for the convex hull stamping of the nickel sheet according to claim 1, wherein the method for extracting the metal transfer rate of the flange area from the corrected fillet radius configuration, simulating the material flow balance from the flange area to the convex hull area, determining the predicted value of the thinning degree of the bottom of the convex hull, comprises the following steps: Extracting geometric parameters of each deformation stage from the corrected fillet radius configuration, obtaining a radial flow velocity field of a flange region through finite element simulation, calculating a metal transfer rate according to the velocity field and the sectional area, verifying mass conservation by adopting a continuous equation, calculating the volume increment of material inflow flux and a convex hull region of each time node flange region, establishing a balance relation between the inflow flux and the volume increment, extracting a thickness value of the bottom of the convex hull according to the balance relation, calculating a thickness reduction amount and a local thinning rate, identifying a thinning serious region according to the spatial distribution of the thinning rate, predicting a subsequent thickness change amount according to the time change rate of the inflow flux of a material, and determining a predicted value of the thinning degree of the bottom of the convex hull by accumulating the current thinning rate and the predicted thickness change amount.
7. The method for acquiring and analyzing the copper male surface morphology data for the nickel sheet convex hull stamping is characterized in that the method for determining the predicted value of the bottom thinning degree of the convex hull comprises the steps of dividing a flange area into a plurality of concentric annular bands along the radial direction, dividing the flange area into a plurality of sectors along the circumferential direction to form a plurality of flange area grids, identifying the inflow and outflow of materials in each grid, acquiring the spatial distribution of the material transfer of the flange area, and predicting the bottom thinning degree of the convex hull.
8. The method for acquiring and analyzing the copper male surface morphology data for the nickel sheet convex hull stamping is characterized by determining a predicted value of the bottom thinning degree of the convex hull, and concretely comprises the steps of dividing a flange area into a plurality of concentric annular bands along the radial direction and a plurality of sectors along the circumferential direction to form grids, arranging flow velocity monitoring points at each grid node to obtain radial and circumferential flow velocity components, calculating mass flux of each grid unit, recording material transfer quantity according to the mass flux difference of adjacent grids to form space distribution data, establishing control body division in the convex hull area, recording thickness change tracks of each control body, and predicting the bottom thinning degree of the convex hull by adopting an interpolation method according to the volume conservation principle in combination with the total amount of inflow materials of the flange area at each deformation stage.
9. The method for collecting and analyzing the copper male surface morphology data for the convex hull stamping of the nickel sheet according to claim 1, wherein the predicted value for the bottom thinning degree of the convex hull is related to the punch stroke and the fillet radius, whether the high convexity requirement is met is judged, if not, a particle swarm optimization algorithm is circularly executed, and the optimized punch stroke parameters are obtained, and the method comprises the following steps: And judging whether the high convexity requirement is met according to the comprehensive evaluation index, initializing the position and the speed of a particle swarm if the high convexity requirement is not met, searching the optimal punch stroke through iteratively updating the speed and the position, and outputting the optimized punch stroke parameter.
10. The method for collecting and analyzing the data of the surface morphology of the copper core for the convex hull stamping of the nickel sheet according to claim 1, wherein the step of evaluating the risk of micro cracks to initiate and propagate along grain boundaries according to the optimized stroke parameters of the punch to generate a dynamic stamping control sequence comprises the following steps: The method comprises the steps of constructing a dynamic stamping finite element simulation environment according to the optimized punch stroke parameters, obtaining stress distribution of each time node through transient dynamics solving, recording stress concentration positions and the change process of the stress concentration positions, judging crack starting conditions according to stress intensity factors by adopting a fracture mechanics method, calculating crack expansion directions, crack expansion rates and damage degrees of all areas, and formulating a staged dynamic stamping control sequence based on the damage degree distribution.

Description

Copper male surface morphology data acquisition and analysis method for nickel sheet convex hull stamping Technical Field The invention relates to the technical field of information, in particular to a copper male surface morphology data acquisition and analysis method for nickel sheet convex hull stamping. Background Nickel sheets, which are a highly conductive, highly ductile metallic material, play a critical role in the fields of electronics, battery connection, and thermal management, and are widely used to achieve reliable electrical connections and efficient heat dissipation paths, particularly in bump formation processes. Current stamping processes face fundamental contradictions between material ductility and forming depth as higher lobe heights are pursued to meet functional requirements. The traditional method increases the height of the convex hull by simply increasing the stroke of the punch, but the static and single loading mode ignores the flow characteristic difference of materials in different deformation stages, so that the rounded corner area at the bottom of the convex hull always bears too high bidirectional tensile stress. The increase in height of the convex hull during the stamping process of the material is accompanied by a sharp increase in the degree of strain concentration in the bottom fillet area, while the fillet radius is a critical geometrical parameter for controlling stress concentration and is constant in the conventional process. The fixed fillet design prevents material flow, the flange area is insufficient in metal transfer to the convex hull area, local severe thinning is caused, the flange area refers to a peripheral flat plate part which does not enter a die orifice or does not generate obvious plastic deformation in a stamping part and is usually positioned in a region pressed by a die blank holder, the convex hull area refers to a three-dimensional convex structure region formed by jacking and local bulging of a plate material by a male die in the stamping process, meanwhile, the fillet radius cannot be dynamically adjusted along with the deformation process, when the ratio of the height of the convex hull to the radius of the fillet exceeds a critical point, the local strain rate rapidly exceeds the uniform extension limit of nickel material, microscopic cracks are initiated along a grain boundary and rapidly spread, and finally the convex hull is cracked. For example, in the production of high convexity nickel sheet bumps, if it is desired to raise the height of the convex hull from 1.0mm to above 1.5mm, the stress concentration in the bottom fillet region can cause the material to reach fracture strain in a very short time, and the forming process fails directly. This contradiction between height and ductility makes it difficult for conventional stamping to break through physical limits. Disclosure of Invention The invention provides a copper male surface morphology data acquisition and analysis method for nickel sheet convex hull stamping, which mainly comprises the following steps: The method comprises the steps of obtaining initial geometric parameters of nickel sheets and material flow characteristic data, analyzing the bidirectional tensile stress concentration degree of a bottom fillet region through stress distribution when the height of a convex hull is increased to obtain a strain concentration index of the bottom fillet region, determining fillet radius configuration corresponding to a deformation stage through a genetic algorithm according to the strain concentration index of the bottom fillet region, judging whether points exceeding the uniform extension limit of materials exist in the fillet radius configuration, if so, obtaining modified fillet radius configuration through iterative adjustment genetic algorithm parameters, if not, directly entering the next material flow optimization analysis, extracting metal transfer rate of a flange region from the modified fillet radius configuration, simulating the material flow balance of the flange region to the convex hull region, determining a predicted value of the bottom thinning degree of the convex hull, relating the punch stroke and the fillet radius according to the predicted value of the bottom thinning degree of the convex hull, judging whether the requirement of the high convexity is met or not, circularly executing a particle swarm optimization algorithm to obtain optimized punch stroke parameters, and evaluating the risk of micro-crack initiation and propagation along a grain boundary according to the optimized punch stroke parameters, and generating a dynamic punching control sequence. The technical scheme provided by the embodiment of the invention can have the following beneficial effects: The invention discloses a copper male surface morphology data acquisition and analysis method for nickel sheet convex hull stamping, which aims at the business scene problems of bottom thinning, stress co