Steel tube - plate connected joint of large crossing transmission towers welding residual stress by numerical simulation
Steel tube - plate connected joint is commonly used in large crossing transmission steel tower , however, in the welding process produced transient thermal stress and residual stress largely, and the large force is eliminated difficultly, so the welding is the main factors affecting the joint, and it is needed to research and analysis. Through the use of large finite element software ANSYS and the thermal coupling analysis method, the indirect method is also used, the life and death of nodes element technique is combined, the temperature field and stress field are numerically simulated, and the residual stress and deformation are analyzed, the residual stress and deformation of the distribution are obtained, so the certain reference value is provided on the actual engineering of the steel tube - plate connected joint.
Residual stress measurements in a cruciform welded joint using hole drilling and strain gauges
Residual stress measurements were made close to the toe of each fillet weld on a load carrying cruciform welded specimen by the hole drilling technique. A standard milling guide with high speed air turbine was used in conjunction with bonded resistance strain gauge rosettes. Experimental calibrations of the method were conducted under known uniform uniaxial tension loads. 
 
 
 
A simple incremental drilling technique was used to determine the stress gradient with hole depth. Measurements were also made both at zero load and known tensile loads in order to study the interaction between residual stresses and the applied loads.
A New Vacuum Pressure Infiltration CFRP Method and Preparation Experimental Study of Composite
In order to prepare a carbon-fiber-reinforced polymer composite (CFRP) with ideal microstructure and properties, a new vacuum pressure infiltration CFRP method is proposed based on an analysis of existing CFRP preparation process methods. Research on composite material preparation systems was carried out by using this new method principle. The system mainly includes a fiber pre-forming module, a vacuum heating infiltration module, a hot-press curing molding module, and a data acquisition control module. Under the conditions of natural curing at 0 MPa + 6 h + 25 °C, vacuum heating curing at –0.05 MPa + 30 min + 80 °C, and hot-press curing at 0.7 MPa + 5 min + 50 °C, a two-dimensional (2D) CFRP with excellent microstructure and properties was successfully prepared. Observing the microstructure of the prepared composite material, it can be found that the inside of the composite material was sufficiently and uniformly infiltrated, and common preparation defects such as holes and delamination were effectively controlled. Through the performance test, the bending strength of the material reached 790 MPa.