How to calculate the flanging pressure

1. Mechanical property index? For this aspect, I suggest you read the books on stamping technology. Here I will briefly introce several items: 1. Yield strength: the ability to resist plastic deformation; 2. Tensile strength: the ability to resist tensile fracture; 3. Elongation after fracture; 4. Yield ratio: the ratio of 1 to 2. Together with the three items, it indicates the plastic ability of the material, and the higher the three items are, The lower the four terms, the better the plasticity of the material. 5, n value, hardening index, the higher the yield strength caused by the increase of deformation degree ring the plastic deformation process. The larger the value, the more stable the forming, the less wrinkling, the better the drawing performance. 6, R value, thickness anisotropy coefficient, the ratio of plate plane strain to thickness strain, The larger the value is, the lower the thinning degree in the thickness direction when the sheet is stretched. The more difficult it is to thin and crack. The above items must be listed in the quality guarantee of sheet metal. Besides, there are also some items such as Alison value, which need you to read by yourself,

2. The difference and relationship between allowable extrusion stress and allowable stress in mechanics of materials:
for most metals, the allowable compressive stress is larger than the allowable tensile stress, so the allowable tensile stress is usually used as the evaluation preparation. Of course, if the research object only has the compression condition, it can be another matter. In addition, the tensile strength in many standards is obtained under the compression condition, It will be specially indicated.

3.

L=0.5 π×( R + K coefficient × T) ×(θ/ 90)

L: developed length of sheet metal

R: inner radius at the bend

t: material thickness

θ: Bending angle

y coefficient: a constant determined by the position of the neural bend line, and its default value is 0.5 (so-called "bend line"). The default value of initial can be set in config_ bend_ factor

extended data:

sheet metal processing is called sheet metal processing. For example, the use of plate to make chimneys, iron barrels, oil tanks, ventilation pipes, elbow big and small ends, Tianyuan place, funnel-shaped, etc., the main process is cutting, bending buckle edge, bending forming, welding, riveting, etc., which requires some geometric knowledge

sheet metal parts are sheet metal parts, which can be processed by stamping, bending, stretching and other means. A general definition is the parts with constant thickness in the processing process. Corresponding to casting parts, forging parts, machining parts, etc., for example, the iron shell outside the car is sheet metal parts, and some stainless steel cabinets are sheet metal parts

modern sheet metal technology includes: filament power winding, laser cutting, heavy processing, metal bonding, metal drawing, plasma cutting, precision welding, roll forming, sheet metal bending, die forging, water jet cutting, precision welding, etc

4.

σ 1.2.3 represents the magnitude of principal stress in stress state σ 1> σ 2> σ 3

for tensile stress σ T is used for compressive stress σ C stands for

The tensile stress is the reaction of the object to the external force which makes the object tend to stretch

the external force on the material is called external load, and the reaction force inside the material is called stress. When an object is pulled at both ends, the tensile stress along its axis is the tensile stress

2. Compressive stress refers to the stress that resists the compression tendency of the object

when a cylinder is compressed at both ends, the stress along its axis is the compressive stress. It is not only the compressive stress caused by the force on the object, but also any compression deformation, including the expansion of the object

extended data:

the normal stress on the axial tension (compression) cross section is equal to the axial force of the section divided by the area of the cross section. In axial tension, the specified normal stress is positive; In axial compression, the normal stress is negative

Although the derivation process of the normal stress formula on the cross section of

axial tension (compression) bar is relatively simple, it integrates the geometric, physical and static considerations. Considering these three aspects comprehensively. It is also applicable in deriving the stress calculation formula of other basic deformations

if it can be determined σ According to the above formula, the distribution law on the cross section can be determined σ The calculation formula of normal stress. The experimental observation shows that the deformation of longitudinal fiber on the surface of axial tension (compression) bar is uniform

The deformation of the longitudinal fiber in the member can be obtained by plane assumption. The so-called plane assumption is: it is assumed that the cross section of a member is plane before deformation, but still plane after deformation. According to the plane assumption, the uniform deformation of the longitudinal fiber on the surface of the member and the Hooke's law of axial tension (compression), the normal stress at each point of the cross section can be considered σ It's also uniform

5.

Formula:

d0 = DM-2 (h-0.43r-0.72t0)

d0: preformed aperture

DM: flanging pitch diameter

H: flanging height

R: Die fillet

t0: material thickness

6. 36t

7. The inner diameter and outer diameter of the hole are R1 and R2 respectively; Mandrel outer diameter R; The room temperature is t0
the radial thermal expansion of the hole is delta 1 = A1 * (r2-r1) * (600-t0)
the radial thermal expansion of the spindle is delta 2 = A2 * r * (600-t0)
the interference can be obtained by combining the calculation results of the above formula with the initial clearance
then look up a book called "design, calculation and assembly and disassembly of interference fit", written by Xu dingqi, which gives the formula for calculating the interference fit pressure according to the interference amount

8. system pressure × Square of cylinder diameter of pressing cylinder × 3.14/10000 × The number of pressure cylinder, more accurate, also need to subtract the spring force