What are the non member and rod system components and structures in civil engineering?

The rod structure is composed of several rods, which is widely used in civil engineering, construction, machinery, ships, water conservancy and other projects. Multi-span statically fixed beams, continuous beams, trusses, rigid frames, arches, suspension structures, grid structures and curved beams are all rod structures.

Members in a rod system structure can be divided into straight rods and curved rods according to their geometric shapes. Straight rods include commonly used beams, columns, shafts, etc.; The most common type of curver is the arch.

According to the form of the node, the rod structure can be divided into: a truss composed of straight rods and hinged joints, a rigid frame composed of rods and rigid nodes, and a hybrid frame where two nodes coexist, if the load on the truss only acts on the node, then each member only bears the axial force (tension or compression).

If the junction structure does not fully meet the requirements of the hinge, a small amount of bending and shear stresses will be generated in the member, even though the axial forces are the main ones, the so-called secondary stresses. The members in the rigid frame are mainly subjected to moments, but also axial and shear forces.

Civil engineering is a first-level discipline, and the registration is generally based on the second-level discipline when taking the postgraduate examination. The secondary disciplines of civil engineering include: structural engineering, geotechnical engineering, earthquake prevention and disaster mitigation engineering, engineering mechanics, bridges and tunnels, etc.

If you are studying industrial and civil construction, you will generally take the structural engineering exam, and the examination subjects include:

Politics (including Ma Zhe, Mao Deng.

3. Modern and modern history, current affairs) 100 points;

Mathematics I (Advanced Mathematics, Probability and Statistics, Linear Algebra) 150 points;

English 100 points;

Specialized courses (generally structural mechanics or material mechanics, which are set by each school.) For example, Dalian Institute of Technology is to take the material mechanics test, Tianjin University is to take the structural mechanics test, Tongji University is to take both subjects, and Chongqing University is to choose one of the two subjects) 150 points.

The structure is composed of several members, which is widely used in civil engineering, construction, machinery, ships, water conservancy and other projects. In a rod structure, the junction of several members is called a node (also known as a node). At each node, there must be no relative linear displacement between the rod ends.

Nodes are divided into hinged nodes and rigid nodes.

On the hinge points, the angles between the members can be changed freely, and the hinge points cannot transmit moments. On the rigid junction, the angle between the members remains the same, and the rigid junction transmits the moment.

For the rod structure, the internal force distribution, deformation and stability under the influence of various factors (such as load, support settlement, temperature change, etc.) are mainly studied. It provides a basis for seeking a safe, effective and economical structural form and checking the strength, stiffness and stability of the structure.

Type 1 of member structure: The structure is made of building materials, and the structure that can bear and transmit the load and play the role of a skeleton is called an engineering structure. Such as: beam and column structures, bridges, culverts, dams, retaining walls, etc.

Concrete structures can be divided into member systems and non-member systems according to the (member shapes).

The three types of concrete structures are: plain concrete structure, reinforced concrete structure, and prestressed concrete structure.

Plain concrete structure refers to a concrete structure without reinforcement or without stress reinforcement. Plain concrete is for reinforced concrete, prestressed concrete, etc., plain concrete is made of cement, sand, stones, admixtures, mixed with a certain proportion of water after a certain proportion, it is mixed with reinforced concrete The main difference is that plain concrete is not equipped with steel bars.

Reinforced concrete structure, refers to the concrete with an appropriate amount of steel bars, with steel bars and concrete made of this structure, steel bars can withstand tensile force, concrete can withstand pressure, has the advantages of solidity, durability, good fire performance, and than steel structure saving steel, the cost is greatly reduced.

Prestressed concrete is to use the tensile and rotten high-strength prestressed steel bars in the concrete to extrude the concrete before the concrete structural components bear the load, and the precompressive stress generated can offset most or all of the tensile stress caused by the external load, which also improves the crack resistance of the structural components.

Rheological performance evaluation index:

Slump is the most widely used and the simplest test method to test and evaluate the fluidity of concrete in the world, however, with the advancement of concrete technology, slump is no longer the only index to evaluate the fluidity of concrete. For example, the yield stress is also an important index to evaluate the workability of concrete, and the concrete can only flow when the yield stress is below a certain critical value.

However, in self-compacting concrete, in addition to slump and yield stress, its cohesion and stability must also be considered. Therefore, large flow concrete requires a small yield value, and self-compacting concrete requires a large plastic viscosity.

When preparing self-compacting concrete:

It must be considered that the system has enough slurry and that the slurry has enough viscosity to settle the aggregate of the concrete mixture under its own weight during the flow process. When the viscosity of the slurry composed of cementitious materials in the system does not meet the requirements, the addition of thickeners should be considered.

The focus of consideration in the design of large fluidity concrete mix ratio is the selection of superplasticizer and the control of water consumption, while the amount of slurry, the volume content of aggregate, the selection of admixtures and the selection of thickeners should be considered in the design of self-compacting concrete.

Hello, a planar member structure is a planar member system composed of several members that can support loads, but any draft of a member system may not be used as a structure. In this section, the composition and rational form of the structure are studied.

Prerequisite: Regardless of the strain of the material after the structural force is applied, each member of the structure is regarded as a rigid member that is completely undeformed. Just film:

Sun Jingyun Zeliang imagines a rigid object that is completely undeformed in the plane called a rigid piece. In a planar member system, a straight, folded, or curved bar can be considered as a rigid piece, and a geometrically invariant system consisting of these members can also be considered as a rigid piece. The distance between any two points in the film remains the same, that is, the position of any point in the film can be determined by the position of a straight line between any two points in the film.

Therefore, a straight line in the rigid sheet can represent the rigid sheet.

Answers]: a, b, c, d

The basic forms of force on structural members can be divided into: tension, compression, bending, and shearing.