What are the different types of torsional members of reinforced concrete?

in the building structure.

There are many situations in which the structure is torsional, such as crane beams, frame side beams, awning beams, etc. However, in actual engineering, there are very few cases in the pure torque action, and most of them are in the bending moment.

Compound torsion under the combined action of shear force and torque.

in structural design.

due to the use of cast-in-place reinforced concrete structure.

Or prefabricated components with large cross-sectional dimensions, relative to bending moment, shear force, axial force, torsion is a secondary factor, in the structural design does not play a controlling role, so often ignore its influence or use conservative calculation methods and structural measures to deal with. In recent decades, with the improvement of material strength and the development of architectural art, the size of components has become smaller and smaller, the structural span has been expanding, and special-shaped components have continued to appear, all of which have made the torsional effect prominent.

In addition to translational vibration, the building structure will also be torsional under the action of **. Seismic damage surveys have shown that torsional action can aggravate structural failure and in some cases become a major factor in structural failure.

Common torsional components include crane beams, awning beams, side beams of cast-in-place frames, curved beams, etc. For reinforced concrete components under normal reinforcement conditions, under the action of torque, the longitudinal bars and stirrups yield first, and then the concrete is crushed, which is ductile failure.

If the longitudinal bars and stirrups do not match, and the ratio of the two reinforcements is quite different, then there is only one yield of the longitudinal bars and stirrups during failure, which is also ductile failure, but the cross-sectional ductility is smaller than that of the suitable bars. The reinforcement ratio of longitudinal bars and stirrups is too high, and the longitudinal bars and stirrups do not yield, while the concrete is crushed first, which is brittle failure and is avoided in the design.

Torsional member is a basic member, and torsional member is divided into two categories according to the force characteristics:

1. Equilibrium torsion** is a torsion directly caused by the load and can be solved by static equilibrium conditions, and has nothing to do with the stiffness of the component. Such as: canopy beams, curved beams, frame side beams, crane beams, folding beams.

2. Constrained torsion**In a superstatically determined structure, torque is generated due to the deformation of adjacent components being constrained, and the magnitude of torque is related to the torsional stiffness of torsional members. For example: continuous beams in the floor.

Note: In a superstatically determined structure, the torque is generated by the restraint of the deformation of the adjacent member, and the magnitude of the torque is related to the torsional stiffness of the torsional member.

For the constrained torsion, due to the nonlinear nature of the torsional member in the process of stress, the torque magnitude is related to the stiffness ratio of the member in the stress stage, which is not a fixed value, and the internal force redistribution needs to be considered for torque calculation.

Page 90 of the 16G101-1 atlas is clearly stated.

1. When the torsional reinforcement is not less than the structural reinforcement, the structural reinforcement can be replaced.

2. Lap joint and anchorage of structural steel bars.

15d can be taken, and the torsional reinforcement is the longitudinal reinforcement of the lower part of the beam.

Summary. Hello, failure form: 1. Failure of less reinforcement, 2. Failure of super reinforcement, 3. Failure of partial excess reinforcement, 4. Failure of suitable reinforcement.

Failure characteristics: 1. Failure of less reinforcement: as soon as the crack is formed, the component is destroyed immediately, the cracking torque is equal to the failure torque, and the failure characteristics are similar to plain concrete, with obvious signs and brittle failure;

2. Over-reinforcement failure: the steel bar is not yielded, and the concrete between the oblique cracks is crushed and destroyed, without obvious warning, brittle failure;

3. Partial super-reinforcement failure: the reinforcement strength ratio of longitudinal reinforcement and stirrup is not suitable, and the longitudinal reinforcement or stirrup does not yield when it is destroyed, and the shaping is better than 1 and 2, but worse than 4;

4. Suitable reinforcement failure: the reinforcement ratio of the torsional longitudinal bar and the torsional stirrup is suitable, after the component is cracked on three sides to produce 45 degrees of oblique cracks, the torsional steel bars intersected with the oblique cracks can be continuously loaded after yielding, until the fourth side is crushed and shaped and damaged.

In addition to the compressive bending and shear effect, the concrete structure will also be subjected to torsional action, and the failure of reinforced concrete pure torsional members is summarized.

Hello, failure form: 1. Failure of less reinforcement, 2. Failure of super reinforcement, 3. Failure of partial excess reinforcement, 4. Failure of suitable reinforcement. Destruction characteristics:

1. Broken stove with less ribs: as soon as the crack is formed, the component is destroyed immediately, the cracking torque is equal to the failure torque, and the failure characteristics are similar to plain concrete, with obvious dust or premonitions, and brittle failure; 2. Over-reinforcement failure: the steel bar is not yielded, and the concrete between the oblique cracks is crushed and destroyed, without obvious foreshadowing, brittle failure; 3. Partial over-rib failure

The ratio of the strength of the longitudinal bars to the stirrups is not suitable, and the longitudinal bars or stirrups do not yield when they are damaged, and the shaping is better than 1 and 2, but worse than that of 4. 4. Suitable reinforcement failure: the reinforcement ratio of the torsional longitudinal bar and the torsional stirrup is suitable, after the component is cracked on three sides to produce 45 degrees of oblique cracks, the torsional steel bars intersected with the oblique cracks can be continuously loaded after yielding, until the fourth side is crushed and shaped and damaged.

Hope it helps.

There are three main types: partial over-rib failure, over-rib failure, and less tendon failure.

If the longitudinal reinforcement and stirrup do not match, and the ratio of the reinforcement between the two is quite different, then there is only one yield of the longitudinal reinforcement and stirrup during the failure, which is also ductile failure, but the sectional ductility of the suitable reinforcement failure is small.

The over-reinforcement failure is a torsional member of the super-reinforcement, the reinforcement ratio of the longitudinal reinforcement and stirrups is too high, the longitudinal reinforcement and stirrups do not yield, and the concrete is crushed first, which is a brittle failure, which is avoided in the design. The destruction of less reinforcement is a torsional component with less reinforcement, and the longitudinal reinforcement and stirrup configuration are too few, and it is stuffy and damaged when torsional, which is brittle failure and is avoided in the design.

The axial tension member is an axial compression column; The eccentric tension member is the upper chordFrame structurecolumns, etc.

When the external force on the member is applied to the centroid of the member section.

When coincident, the stresses generated by the cross-section of the members are uniformly distributed.

This kind of member is an axial stress member. Axial stress members are widely used in load-bearing steel structures, such as roof trusses, brackets, towers, grids and reticulated shells and other types of plane or space lattice systems and support systems.

The pressure application point of the component deviates from the axis of the component, so that the component is both compressed and bent when it is eccentric compression member (also known as compression-bending member). It is commonly found in the upper chords of roof trusses, frame structural columns, brick walls and brick stacks. When subjected to the same external tension force, the stress of the eccentric tension member is much higher than that of the axial tension member, so it is in the structural design.

Such components should be avoided as much as possible.

According to the different forces and deformations, what are the basic components of reinforced concrete?

Dear, I'm glad to answer for you: according to the different forces and deformations, what are the basic components of reinforced concrete? A:

According to the characteristics of the width of the bucket, the basic components are divided into: bending members (beams, plates) cavity simplification; compressive members; tensile members; Torsional members, etc.;; the end "Reinforced Concrete Structure"; Directory; 1) according to the use to divide the bridge structure; The classification of reinforced concrete structures is generally divided into four types:

Frame structures, shear wall structures, frame-shear wall structures, and barrel structures. 1.The frame structure is a longitudinal and transverse frame composed of beams and columns.