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steel structure is a structure composed of steel materials and is one of the main types of building structures. Across the world, especially in developed countries and regions, steel structures have been reasonably and widely used in the field of construction engineering. The steel structure is mainly composed of beams, steel columns, steel trusses, and other components made of section steel and steel plates, and adopts rust removal and anti-rust processes such as silanization, pure manganese phosphating, washing and drying, and galvanizing. Each component or component is usually connected by welds, bolts, or rivets. Steel structure applications are mainly used in bridges, buildings, lighthouses, ships, and other fields. In addition to steel structures, there are also wooden structures, concrete structures, brick-concrete structures, and other structures.
Steel structure material performance indicators
1. Strength: The strength index of steel consists of elastic limit σe, yield limit σy, and tensile limit σu. The design is based on the yield strength of steel. High yield strength can reduce the self-weight of the structure, save steel, and reduce construction costs. The value of ‘σu/σy can be regarded as a parameter of steel strength reserve.
2. Plasticity: The plasticity of steel generally refers to the property of significant plastic deformation without fracture after the stress exceeds the yield point. The main indicators to measure the plastic deformation ability of steel are elongation δ and area reduction ψ.
3. Cold bending performance: The cold bending performance of steel is a measure of the steel's resistance to cracks when plastic deformation occurs during bending processing at room temperature. The cold bending performance of steel is to use the cold bending test to test the bending deformation performance of the steel when it withstands the specified bending degree.
4. Impact toughness: The impact toughness of steel refers to the ability of steel to absorb mechanical kinetic energy during the fracture process under impact load. It is a measure of the resistance of steel to impact load. It may cause brittle fractures due to low temperature and stress concentration. A mechanical property. The impact toughness index of steel is generally obtained through the impact test of standard specimens.
5. Welding performance: The welding performance of steel refers to obtaining welded joints with good performance under certain welding process conditions. Welding performance can be divided into two types: welding performance during the welding process and welding performance in use performance. Our country adopts the welding performance test method of the welding process and also adopts the welding performance test method of usability and usage properties.
6. Durability: Many factors affect the durability of steel. First of all, steel has poor corrosion resistance, and protective measures must be taken to prevent steel from corroding and rusting. Secondly, because the damage strength of steel under high temperatures and long-term load is much lower than the short-term strength, the lasting strength of steel under long-term high temperatures must be measured. Steel will automatically harden and become brittle over time, a phenomenon known as "aging." The impact toughness of steel materials under low-temperature load should be tested.
