Static Test Study And Stability Analysis Of Concrete Pseudo-cylindrical Ribbed Folded Plate Shel

Concrete quasi-cylindrical multi-ribbed folded plate-shell structure is a new type of long-span concrete spatial structure,which can give full play to the compressive performance of concrete In order to provide a scientific reference for practical engineering application of concrete quasi-cylindrical multi-ribbed folded plate-shell structure system,the static behavior,elastic stability and geometrical nonlinear stability of concrete quasi-cylindrical multi-ribbed folded plate-shell structure system are studied by combining static test with numerical results The main contents and achievements of the study are as follows:1.Firstly,the finite element theory is used to analyze the static performance of the structure.After obtaining the basic mechanical performance of the structure,the static performance parameterization analysis is carried out to obtain the structural force law.It is found that the maximum tensile force of the structure is in the tension beam,and the maximum pressure is in the column.The internal force of the main arch beam is significantly greater than the internal force of the transverse ribbed beam,and the internal force of the transverse ribbed beam is also significantly greater than the internal force of the longitudinal ribbed beam.The structure has strong arched force transmission properties.The aspect ratio has the greatest impact on the vertical displacement of the structure among various parameters.2.Conduct static test research on the scaled model of the structure.Based on a plane size of 18m×The prototype structure is an 18m concrete pseudo cylindrical multi ribbed folded plate shell,with a scale ratio of 1/6 to create a scaled model.The load design value is 3.8 k N/m~2。By analyzing the deflection and stress-strain curves of the measuring points under various levels of load,the bearing capacity,deformation,and normal performance of the structural system were evaluated.Then the test results and the finite Metacomputing results are compared and analyzed.Research has shown that under the action of design loads,the load-displacement and load-stress relationships of the structure are approximately linear.The maximum vertical displacement occurs at the center of the roof,and the internal force distribution and vertical displacement variation obtained from the finite element model calculation are basically consistent with the distribution pattern shown in the model test results.3.Structural elastic stability analysis.Using the eigenvalue buckling analysis method to study the elastic stability performance of the structure,and providing parameterized analysis,it is found that the first nine buckling modes of the structure as a whole mainly exhibit two forms:positive symmetry about the central main arch or anti symmetry about the central ridge line;Increasing the cross-sectional size of the column has the most significant effect on the critical load of elastic instability of the structure,with a critical load value of 61.32 k N/m~2.4.Structural geometric nonlinear stability analysis.Applying initial defects to the structure using the consistent defect mode method,it was found that the vertical deformation during the instability process of the structure mainly develops from the central dense rib plate to the surrounding area,that is,the central deflection of the roof is the largest.Through parameterization analysis,it is concluded that:(1)the geometric nonlinear buckling critical load of non ideal structures is approximately86.39%of the elastic instability critical load,which is 10.67 times the structural design load.(2)The most significant impact on the geometric nonlinear stability of the structure is the rise span ratio,with a critical load reduction of 59.84k N/m2;Next is the height of the main arch beam section,followed by the height of the ribbed beam section and the size of the column section.