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Comparison of approaches to the assessment of buckling of variously long and supported columns
Ostratická, Klára ; Pokorný, Jan (referee) ; Šebek, František (advisor)
The bachelor's thesis deals with assessment of the buckling stability. The differences between elastic and inelastic buckling and effects on the critical force are described. The effect of material, supports and length of the column is described in more detail. During buckling, the character of deformation changes, the compressed column starts to bend at a definite point. This point is called bifurcation point and the limit is amount of critical force. The calculation of critical buckling force is carried out analytically for selected examples using the Euler and Johnson methods. The results are numerically checked by the finite element method in Ansys. The results for linear buckling are identical. Examples of nonlinear buckling are also calculated numerically. The difference is found in critical force for contact surfaces without friction and with friction. Defining the critical force can prevent the collapse of the entire structure, thus avoiding catastrophic incidents.
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Analysis of possibilities of solution of buckling of a screw-shaped beam
Pokorný, Jan ; Fuis, Vladimír (referee) ; Burša, Jiří (advisor)
Bachelor’s thesis deals with the effect of the pretwist of a column on the increase in buckling load and also focuses on a column with rectangular cross section. This problem is divided into two main parts. The first one is represented by the column with a large thread pitch, the second one by a small thread pitch. The results are obtained by a numerical approach using MATLAB software. The verification is carried out via finite element software. The outcome of this thesis is plotting the ratio of the critical loads of the twisted and prismatic columns against the ratio of the side lengths of the rectangular cross section. The results are shown for both types of considered columns.
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Evaluation of risk of buckling in columns with inaccuracies in geometry and load
Fischer, Jiří ; Fuis, Vladimír (referee) ; Burša, Jiří (advisor)
The aim of this thesis is to analyse applicability range of relations for a critical load at buckling for columns with deflection from ideal column – initially curved column or eccentric load. The solution of this thesis is analytical and it comes from solving the differential equation of the deflection curve. This equation has different general solutions for both assumptions. The result achieved in this thesis is general recommendation for maximal values of eccentricity of load according to cross section. Next result is recommendation of maximum curve according to cross section. The chosen cross sections are circular, square, rectangular and thin tubes.
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Evaluation of risk of buckling in columns with inaccuracies in geometry and load
Fischer, Jiří ; Fuis, Vladimír (referee) ; Burša, Jiří (advisor)
The aim of this thesis is to analyse applicability range of relations for a critical load at buckling for columns with deflection from ideal column – initially curved column or eccentric load. The solution of this thesis is analytical and it comes from solving the differential equation of the deflection curve. This equation has different general solutions for both assumptions. The result achieved in this thesis is general recommendation for maximal values of eccentricity of load according to cross section. Next result is recommendation of maximum curve according to cross section. The chosen cross sections are circular, square, rectangular and thin tubes.
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Analysis of possibilities of solution of buckling of a screw-shaped beam
Pokorný, Jan ; Fuis, Vladimír (referee) ; Burša, Jiří (advisor)
Bachelor’s thesis deals with the effect of the pretwist of a column on the increase in buckling load and also focuses on a column with rectangular cross section. This problem is divided into two main parts. The first one is represented by the column with a large thread pitch, the second one by a small thread pitch. The results are obtained by a numerical approach using MATLAB software. The verification is carried out via finite element software. The outcome of this thesis is plotting the ratio of the critical loads of the twisted and prismatic columns against the ratio of the side lengths of the rectangular cross section. The results are shown for both types of considered columns.
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