STABILITY OF METAL SINGLE BELT MESH DOMES WITH INITIAL IMPERFECTIONS

Abstract

 Recently, in the practice of constructing large-span spatial coatings, shallow mesh 
domes  have  been  used  more  often  than  others.  Such  designs  make  it  possible  to  form  a  smaller 
building volume, but their work under the influence of loads is much more complicated. And now 
the problems of calculating the stability of such domes are not sufficiently solved. The main reason 
is the difference between the experimental results and the performed calculations. The actual shape 
and  position  of  the  nodes  of  the  mesh  dome,  as  well  as  its  actual  stress-strain  state  during 
exploitation, differ from the state performed by the project. Accumulated deviations of the surface 
geometry  of  the  dome  during  installation,  manufacturing  defects  significantly  change  the  ideal 
design scheme, which was used in the calculations, and increase the probability of loss of stability. 
The  stability  of  shallow  metal  single-belt  mesh  domes  with  initial  shape  imperfections 
obtained in the process of erection of the structures is considered.  
The  mesh  dome  was  replaced  with  a  continuous  one  and  its  nonaxisymmetric  deformation 
with loss of stability from bifurcation loads was analyzed. 
The  classification  of  the  initial  imperfections  obtained  by  the  structure  during  construction 
and mounting and the deviations of the loads applied to the structure is given. It is shown that the 
greatest influence on the loss of stability of a shallow spherical dome has imperfections in the shape 
of the middle surface. 
The  approaches  that  lead  to  the  convergence  of  discrepancies  between  the  results  of 
experimental critical loads of stability loss and theoretical are determined. In calculating stability, it 
is most important to take account of the initial imperfections of the form and the nonaxisymmetric 
deformation of the spherical dome, taking into account imperfections. 
For  engineering  calculations,  the  stability  loss  of  shallow  mesh  domes  is  obtained  by  a 
dependence that allows you to adjust the critical load to take account the amplitude of the measured 
initial imperfections of the constructed structure. 
 For  the  purpose  of  further  research,  it  is  important  to  investigate  the  effect  of  artificially 
created initial deviations of the  mesh dome nodes  from the  ideal spherical shape  in the direction 
opposite  to  the  loss  of  stability,  due  to  which  a  significant  increase  in  the  critical  load  can  be 
achieved.