The establishment of the optimization model of stamping direction is the automatic or semi-automatic design carried out on the computer in the way of man-machine combination or automatic exploration according to the optimization principle and method, which integrates various factors. Through optimal design, the best design scheme under the existing engineering conditions can be selected. The optimal value in design refers to the optimal design value that can be obtained under the influence of various design factors under certain conditions. Optimal value is a relative concept, which is different from the extreme value in mathematics, but in many cases, it can be expressed as the maximum or minimum value
for any panel mold designer, he always hopes to obtain the optimal design scheme, so that the designed mold has the best use performance and the lowest material consumption and manufacturing cost, so as to obtain the best economic and social benefits. Therefore, the method of optimal design should be adopted
the determination of the best stamping direction of the panel is to select the best coordinate position of the panel in the mold, that is, the rotation angle of the panel around the coordinate axis. Because the determination of the stamping direction of the panel is determined by many factors, to determine the optimal value of the stamping direction, we must make the comprehensive index including these factors reach the optimization, which involves the optimization of the multi-objective function. The relative importance of multi-objective functions and their differences in dimension and magnitude. The expression of the objective function is where x design variable fjx the WJ weight of the first objective function FX the final objective function according to experience, generally take 150140 of the maximum depth of the section as the initial contact part, and the section below 3 lines is perpendicular to the 2 axis. Considering the contact state and feeding resistance between the punch and the sheet metal at the beginning of deep drawing, the objective function of single objective optimization is established by using the intersection of the cross-section shape and the contact line 38, the contact part between the punch and the sheet metal, as follows: 1.1 the initial contact area is as large as possible, that is, maxf1a is the optimal value of the target in the feasible region. The contact area in the section is the length of the contact part. Since the height of the contact line remains unchanged, the length of the line segment of the intersecting part can be used
the distribution uniformity of the initial contact points is evaluated by the difference between the intersection of the section and the contact line, the average value of the coordinates and the geometric center coordinates of the section shape. In the feasible region, 2,0 is the optimal value of the objective function
the dispersion of the initial contact point is the intersection of the section and the contact line, and the difference between the maximum and minimum coordinates. The dispersion degree of the initial contact point is the optimal value of the target in the feasible region
the optimal value of the uniformity of feed resistance
in the above expression, it is the number of segments of the intersecting part, and 1 is the coordinates of the starting point, the ending point and the midpoint of the first intersecting part, which are the geometric center of the cross-section; Is the coordinates of the start and end points of the section shape
in order to comprehensively optimize each objective in the question under consideration, the evaluation function method is used to transform the multi-objective optimization into a single objective optimization question. The evaluation function can be, which is a public feasible region. The evaluation function formed by this method of weight coefficient reflects the degree that the value of each single objective function leaves their respective optimal value, which determines the optimization method of the flood direction of the panel. Shan, the corresponding corner is the stack handle, you Chong Jin Rou, 2, 0 determination of the best punching direction in the system. When using the optimization method to determine the punching direction, first cut several sections perpendicular to the axis along the 2 axis according to a fixed step, set the number of sections as a record, and then analyze each section to determine the search range of the feasible region angle of the design variable, and find the intersection of the feasible regions of all sections, Then we can get the common feasible region of the design variable in the 2 direction, that is, the search range of the rotation angle around the axis. In the public domain, the stamping direction of each section is optimized. Finally, the rotation angle of the drawing part around the 2-axis is obtained by weighted average of the rotation values of all sections. Similarly, along the axis, take the number of sections perpendicular to the axis as the meaning. When determining the feasible region of a single section with the same 2.1 feasible region of a single section, define the design variable 1 in the plane where the section is located as the angle of rotation of the section shape around the origin of the coordinate axis, that is, the angle of the drawing part around the coordinate axis. Specify the definition that the clockwise direction is positive or leave 10 tons of recyclable steel? " Shan yinmu, chairman of Hangxiao Steel Structure Co., Ltd., often puts forward that the problem domain is 2
in the process of determining the stamping direction, the constraint is that there must be no dead zone. Set the vertical direction as the punching direction. To judge whether an angle meets the constraint conditions, you can use the vertical line intersecting with the section shape to calculate the number of intersections. When the line segments coincide, the number of agreed intersections is zero. If the constraint conditions are met, the number of intersections will not be more than 1 This method is very intuitive, but it requires frequent intersection, and the program is inefficient. It can be judged according to method 2
scatter the section shape according to the fixed step distance to obtain a group of discrete points, and calculate the angle between the vector direction VI connecting the two discrete points and the X axis from left to right. So, you can get the feasible area team with poor transaction to the corner of section 1! 6 and domain width 01 When the following judgment is made according to the domain width, there is no solution, that is, it does not meet the process requirements of stamping forming; 01=, the value is zero, that is, there is a unique punching direction; C start to input the drawing part shape factory plan, and withdraw the drawing number
the feasible region of the grate section of the dare surface data
whether it meets the requirements of the work, whether it meets the requirements of the public and soldiers in the feasible area, whether it meets the requirements of the work, or whether it meets the search of the fixed bag in the existing direction 01 When, there are countless solutions, that is, it needs to be optimized; 2.2 determination of public feasible region after the feasible region of each section is determined, the public feasible region of each section corner can be obtained, so be careful 0! 4. When pressing, any pressing direction cannot meet the requirements of stamping process; When 0, 08=, there is only one punching direction; When the juice is 80, it needs to be optimized; 3 optimization calculation of stamping direction RA sections are taken along the Z axis and n sections and 3 planes are taken along the X axis of the deep drawing part. After the feasible regions around each axis are determined respectively, the above formula is used to calculate the optimal rotation angle of each section by using the search method, and then the weighted average is determined to determine the single section stamping direction around the 2 axis or the 4 axis. The determination examples 15.975 and 15.08 are relative to the current position. After optimization calculation, the optimal rotation angle is 7.69, 48
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