The Materials Testing And Parameters Evaluation For Structural Steel Q345GJ

The new domestic series of high-performance steel GJ is the quality of upgrading and transforming steel for construction, which has a better overall performance than low-alloy high-strength structural steel used generally in present (particularly for the thick plate and super thick plate). Now it has been used in several construction projects, such as The Main Stadium for Olympic Games, the new airport in the national capital, CCTV new building.The production standard(《Steel Plates For Building Structure》GB/T19879-2005) related to high-performance GJ structural steel has been promulgated in 2005, but the design standards or blanks are still revising《.Technical Specification For Steel Structure Of Tall Buildings》(JGJ98-99) is being revised , with one part of its contents is placing the home newest development production high performance GJ structural steel into this regulation, that can speed up the domestic structure steel products turning to a new generation with superior win and the inferior wash out.《Unified Standard For Reliability Design Of Building Structure》GB50068-2001 (referred as"Unified Standard"in under-mentioned)impact that , the main factors affecting resistance of structural component are material properties M, geometric parameters A and computing models P, which are all random variables. The variabilities of these factors lead to the uncertainty of resistance. So the statistical parameters of uncertainty and standard value of resistance must be determined for offering basis to the relevant codes and rules.In view of the above-mentioned questions, this paper obtains a large number of material property data and section geometric size for Q345GJ series steel products through the independent tests and the investigation and study, considers the influences of the loading speed for tests and the testing machine flexibility to material performance, uses mathematic statistical methods for analysis, get the probability distributions of materials strength and section geometrical property for Q345GJ steel to meet the normal distribution law. Unifies the structure degree of security theory according to《Unified Standard》, gains that statistical charaters, proposes the suggestion values for design parameters, and gives a certain of efficient analysis.The contents researched in this paper are the fundamental researches (including tests and analysis) for revising design standards of GJ series structural steel, the achievements may provide a reference for formulating regulations. Meanwhile that will have promoter action of extending the application for the GJ series steel in greatly cross and high-rise constructions, assurance the security and economy for structure, accelerating the replacement from tradition construction structure steel to the new GJ series steel products in domestic metallurgical industry.