Hole Expansion

Hole Expansion

 

(in Russian, raskatka), an operation during forging that increases the external and internal diameters of a ring-shaped pierced billet with an insignificant increase in length as a result of reduced wall thickness. The operation is performed with a press or hammer. The billet is heated to forging temperature and placed on a mandrel mounted on two supports; the mandrel serves as a base or bottom die, and the top die is narrow and long. The billet is forged between the two dies and is rotated after each compression. The operation is used for making relatively large-diameter ring-shaped parts.

R. M. GOLUBCHIK

Mentioned in ?
References in periodicals archive ?
The purpose of the hole expansion (HE) test is to assess edge stretching performance of sheet metals, where a punch is forced through a prepared hole until edge cracking occurs.
f] are the initial and final specimen hole diameters, and [lambda] is the hole expansion ratio.
Hole expansion testing is fraught by excessive uncertainty and variation, and the results of which can be heavily influenced by specimen preparation technique and human subjectivity.
The hole expansion ratio ([lambda]) is generally regarded as a relative "local formability" parameter with limited application to edge-cracking analysis and prediction.
In the following a data analysis methodology is described, where a constrained statistical approach is used to identify hole expansion (HE) test data outliers.
We have proposed our very first algorithmic solution to deal with a possibly new and challenging problem of hole expansion in WSN.
This is because for a larger DNT the network acts slower with the hole expansion and hence, a number of new dead nodes cannot get reported fast enough.
Most challenging, perhaps is the concern that the hole expansion speed is normally unforeseeable and hence, we face a big trouble: a parameter set that is nicely suitable to a fast expansion setting can perform very poorly in a slow expansion setting.
The first system will be dedicated to measuring strains in sheet metal tests such as the hole expansion test, forming limit test and the limiting dome height test and will be permanently attached to our sheet metal forming tester.
Situation B: Detect-to-undetected Node (DTUN): DTUN also has two possibilities: phenomenon shrinkage or hole expansion inside the phenomenon.
Bearing, clamped, and adhesive modes of load transmission are all considered, as well as bearing mode with hole expansion.