Stone composing – Wikipedia

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L’ That’s compost It is that structural element, generally in steel, consisting of several assembled parts.
The use of the composed auctions was introduced to remedy the stability limits of the elements normally on the market and in particular to the technical difficulties established by the phenomenon of the peak installation.

There are basically two types of compound rods:

Aste calastrellate;
Flooring rods.

Aste calastrellate [ change | Modifica Wikitesto ]

The calastillate rods are made up of traditional profiles assembled, in fact, with Calastrelli, or connection elements welded to the profiles themselves. The overall behavior is chassis and the Calastrelli work mainly to flexion and cut.

To understand the deformation due to the cutting, it is necessary to consider a trellis module. It is considered that this form is urged by a unitary force so that the cutting deformation coincides with the deformability to cut:

{Displaystyle gamma = {fraud {t} {fra {ga} {chi}}} = {fraud {chi} {ga}} = {fraud {eta} {l_ {0}}}}}}}}

Therefore it is necessary to evaluate the movement of the point of application of the unitary force with the principle of virtual work:

{Display 1Cdot ETA = 4int _ {0}}}}}}}}}}}}}}}}}}}} {e__}} , dxi + 2int _ {l_ t}}}}}}}} {frac}} {frac}} {frac}} {frac} {frac}} {frac} {frac}} {frac}} {frc}}}}} } xi} {ei_ {c}}}, dxi}

Therefore

{displaystyle eta ={frac {1}{EI_{1}}}left|{frac {xi ^{3}}{3}}right|_{0}^{frac {l_{0}}{2}}+{frac {2l_{0}}{12EI_{c}}}left|{frac {xi ^{3}}{3}}right|_{0}^{frac {l_{t}}{2}}={frac {l_{0}^{3}}{24EI_{1}}}+{frac {2l_{0}^{2}l_{t}^{3}}{24l_{t}^{2}EI_{1}}}={frac {l_{0}^{3}}{24EI_{1}}}+{frac {l_{0}^{2}l_{t}^{3}}{12l_{t}^{2}EI_{1}}}}

{Displaystyle {fraud {eta} {l_ {0}}} = {fraud {l_ {0}^{2}} {24ei_ {1}}}+{fraud } {12l_ {t}^{2} ei_ {1}}}}

Taking into consideration a “Tozzo” Calastrello, that is, it has a relationship

{displaystyle h/l_{t}geq 0,5}

${displaystyle h/l_{t}geq 0,5}$ It is possible to neglect the deformability of this element, therefore

{displaystyle gamma cong {frac {l_{0}^{2}}{24EI_{1}}}rightarrow rho _{1}={sqrt {I_{1}/A_{1}}}rightarrow gamma cong {frac {l_{0}^{2}}{24EA_{1}rho _{1}^{2}}}}

${displaystyle gamma cong {frac {l_{0}^{2}}{24EI_{1}}}rightarrow rho _{1}={sqrt {I_{1}/A_{1}}}rightarrow gamma cong {frac {l_{0}^{2}}{24EA_{1}rho _{1}^{2}}}}$

As follows that for a calastrlata rod it is worth that

{displaystyle lambda _{id}={sqrt {lambda ^{2}+pi ^{2}EA{frac {chi }{GA}}}}={sqrt {lambda ^{2}+pi ^{2}2EA_{1}left({frac {l_{0}^{2}}{24EA_{1}rho _{1}^{2}}}right)}}={sqrt {lambda ^{2}+{frac {pi ^{2}}{12}}{frac {l_{0}^{2}}{rho _{1}^{2}}}}}}

So

{displaystyle lambda _{id}={sqrt {lambda ^{2}+{frac {l_{0}^{2}}{rho _{1}^{2}}}}}}

TRALICCIATE AUTHES [ change | Modifica Wikitesto ]

The pierced auctions are made up of profiles assembled with transverse elements, called pierks, generally united through folk. The behavior of the system is trellis, that is, as a generic reticular beam.

To understand the deformation due to the cutting, it is necessary to consider a trellis module. It is considered that this form is urged by a unitary force so that the cutting deformation coincides with the deformability to cut: