Abstract
The so-called ‘rule of the middle third’ states that an inclined force applied at the top of a vertical pillar with rectangular cross-section must intersect the bottom within the middle third of the height of the rectangle in order that the normal stress on the base is one-signed. This rule has been extended by Michell (1900) to the case of a plane elastic wedge loaded at its vertex. We here study plane elastic pillars with other profiles, like a trapezoid, the plane region bounded by two branches of an equilateral hyperbola, a blunt pillar. The result is that the rule is only partially valid.
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References
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Buratti, G. Some Remarks on the Rule of the Middle Third. Meccanica 39, 97–104 (2004). https://doi.org/10.1023/B:MECC.0000005125.23992.34
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DOI: https://doi.org/10.1023/B:MECC.0000005125.23992.34