Method for designing support arm of bifurcate arborescence arc

Abstract

The invention belongs to the technical field of support arm structures, and discloses a method for designing a support arm of a bifurcate arborescence arc by solving the tree shape optimization modelof bifurcate arborescence support arm. After dimensionless processing; the ratio between the unit rigidity ratio of the trunk arm and the branch arm, the ratio of the angle between the two branch armsand the round angle of the arc is given; the unit stiffness ratio of the trunk arm and the first branch arm and the unit stiffness ratio of the trunk arm and the second branch arm are both 5.67, andthe length ratio of the branch arm to the second branch arm is 1.02; the cross section height ratio and the thickness ratio of the trunk arm and the first branch arm are 1.805 and 1.405 respectively,and the cross section height ratio and the thickness ratio of the trunk arm and the second branch arm are 1.805 and 1.405 respectively; At this time, the integral buckling load of the arborescence branch arm structure is 2.50-4.34 times of the buckling load of the two branch arms, and the volume ratio of the structure is reduced by 37-53%. The support arm has the advantages that the structure is lightest, the buckling load of the integral structure is maximal, and the stability is the highest.

Description

technical field [0001] The invention belongs to the technical field of hydraulic arc gate support arm structures, and in particular relates to a design method for a bifurcated tree arc gate support arm. Background technique [0002] For large hydraulic steel gates, because the span is too large or the gate height is too large or the water head is too high, it will lead to a series of problems such as too much weight of the hydraulic steel gate, insufficient structural rigidity or poor stability of the support arm. From various gate accidents It is found that the crash and damage of the gate is caused by the instability of the support arm caused by severe vibration, and the reason is mainly due to the weak stiffness of the support arm. The arc gate support arm is mainly used to bear the water load generated by the arc gate panel, and is installed on the overflow dam section. In the current "Code for Design of Steel Gates in Water Conservancy and Hydropower Engineering (SL74-...

AI Technical Summary

Problems solved by technology

[0005] With the continuous emergence of high dams and large reservoirs, large-scale hydraulic steel gates have also been continuously developed. However, due to too large spans, too high gate heights, or too high water heads, the use of existing two-arm structures often leads to heavy hydraulic steel gates. If it is too large or the structural rigidity is insufficient or the stability of the support arm is too poor, it will cause damage to the hydraulic steel gate and endanger the lives and property safety of people downstream

In order to make up for the above shortcomings of the traditional two-arm gate structure, a design method for the bifurcated tree-shaped arc gate arm is proposed. The bifurcated tree-shaped arc gate arm designed by this method has the advantages of saving materials and high stability. Advantages, can well solve the contradiction of large rigidity, high stability and light weight of existing large arc doors

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