Exploration of rule design for double-end pull rod of floating head tube bundle
This paper aims at the technical problems in the development and application of the double-end tie rod floating-head tube bundle,based on the existing standards and engineering experience,three technical methods were developed for the design and verification of combined connection structures in the case,which is an innovative structure.An equivalent calculation method for the pull-out force of expansion welded combination tube joints and a weighted equivalent calculation method for the allowable pull-out force of expansion welded combination tube joints was proposed.The technology was applied to the structure strength analysis of the strength welding and the strength expansion of a ring groove in the tube hole.The results indicate that the calculated equivalent pull-out force is conservative and reliable when the welded length is converted to the expansion length,and it is 5.7 MPa.The allowable pull-out force of weld and the allowable pull-out force of strength expansion joint of the composite tube joint are calculated by weighted average,and the equivalent allowable pull-out force obtained is 7.4 MPa,which is closer to the actual engineering situation.However,it is also advisable to consider whether the force trend is positive or negative pull-out,or in the transition zone between positive pull-out and negative pull-out,make appropriate correction.A combination connection structure type of threaded and welded connection between the pull rod and the tubesheet was also proposed,as well as a classification and step-by-step method for verifying their combined strength.The calculation and analysis show that the double-end tie rod of floating-head tube bundle meets the structural strength requirement and the design is feasible.
万方数据
维普
