section crack
1.Based on the analysis of stress and strain on precast beam section at manufacturing, transporting and assembling stages and composite beam section at using stage, calculating methods of normal section crack resistance at corresponding stage are presented by usng the elastic theory, which lays a foundation for subsequent experimental study and application.
3.Using method of finite element, this paper shows that the continuous composite beams have these properties of moment excess in middle span and stress lag of negative steel in abutment. These properties result in plastic redistribution of section internal force between middle span and abutment, which enhance flexure strength, crack resistance and ductility.
5.Bearing capacity of normal cross section, ductility, cracking load and failure characteristics of RLC were studied. The study result suggest that it is applicable of structural design criterion formula of common concrete for HSLC and then calculate formula for crack bending moment of rectangle cross section was revised.
6.Based on the pseudo-static experimental results of nine abnormal joints, the damage process of abnormal joint is divided into four stages of original crack, entire crack, ultimate state and failure, the effect of axial force ratio, stirrup ratio and height of column section on seismic behavior of abnormal joint are discussed, the conclusion that anti-shear capacity of abnormal joint are studied in entire crack state by studying the minor core of abnormal joint is made, the calculating formula for anti-shear capacity of abnormal joint is proposed with a view to asymmetry in stirrup yield.
7.Based on the experiment results, the damage form of abnormal exterior joint are summarized, characteristics of hysteresis curve are studied, the effect of stirrup ratio and height of column section and beam section on anti-shear property of abnormal joint are discussed, working mechanism of abnormal exterior joint is researched, the conclusion that the anti-crack and bearing capacity of abnormal joint are studied by analyzing the minor core of abnormal exterior joint is proposed, the basic data is provided for the design formula of abnormal joints.
10.By the analysis of stress, crack characteristics, cross section metallography, scanning electrometry microscopy, energy spectrum micro-area as well as material quality of top hair clip pipe of Primary reformer, finds out the reason for top hair clip pipe cracking is stress corrosion cracking, and puts forward defending measures.
