Lightening holes

Lightening holes are holes in structural components of machines and buildings used by a variety of engineering disciplines to make structures lighter. The edges of the hole may be flanged to increase the rigidity and strength of the component. The holes can be circular, ovals, or rectangles with rounded edges, but they should never have sharp corners, to avoid the risk of stress risers, and they must not be too close to the edge of a structural component.

Motor racing

Lightening holes became a prominent feature of motor racing in the 1920s and 1930s. Chassis members, suspension components, engine housings and even connecting rods were drilled with a range of holes, of sizes almost as large as the component.

This drive towards lightening was based on a misunderstanding of the component's mechanical behaviour. The assumption for a H girder was that all of the resistance to bending stresses was carried in the two top and bottom flanges of the girder, with the central web only carrying out a spacing function. The central web could thus be drilled indiscriminately, supposedly without weakening the overall girder. This was based on two fallacies: firstly that the only forces on the beam were simple bending forces in the plane of the web. In practice, a more complicated force, such as an unexpected torsional twisting from a sudden suspension bump overloaded the now-weakened central web and the lightened beam failed immediately. Secondly, the assumption that the ideal forces were separated into the top and bottom flanges was increasingly unrealistic with the development of stressed skin and monocoque designs, where loads were more evenly shared. In these designs there was no "unloaded web" that could be safely drilled.

Asshole (album)

Asshole is the second solo album release by Kiss member, Gene Simmons. It was released in 2004 on Sanctuary Records. Due to its controversial title, the album's title does not appear on the front cover of the album. On the side of the CD case the title reads "***hole".

The album contains songs Simmons wrote based on work by Bob Dylan and Frank Zappa, among other musicians, specifically Dave Navarro who plays guitar on the The Prodigy cover "Firestarter".

Track listing

Personnel

Hole (EP)

Hole is an EP by the Sheffield, UK, instrumental post-rock band 65daysofstatic, released on 14 March 2005 on Monotreme Records. The title track is taken from their album The Fall of Math.

Track listing

This EP also contains the video for "Retreat! Retreat!".

External links

Glossary of chess

This page explains commonly used terms in chess in alphabetical order. Some of these have their own pages, like fork and pin. For a list of unorthodox chess pieces, see Fairy chess piece; for a list of terms specific to chess problems, see Glossary of chess problems; for a list of chess-related games, see Chess variants.

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P

[adjective: prophylactic] Prophylactic techniques include the blockade, overprotection, and the mysterious rook move.

Q

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References

Bibliography