A two-scale method to include essential behaviour of bolted connections instructures including elevated temperatures  

作　　者：Qingfeng Xu Hèrm Hofmeyer Johan Maljaars 

机构地区：[1]Eindhoven University of Technology,Eindhoven,5612 AE,The Netherlands [2]TNO,Delft,2628 CK,The Netherlands

出　　处：《Theoretical & Applied Mechanics Letters》2024年第6期496-512,共17页力学快报(英文版)

基　　金：supported by the China Scholarship Council (Grant No.2018-0861-0211).

摘　　要：A two-scale method is proposed to simulate the essential behavior of bolted connections in structures includingelevated temperatures.It is presented,verified,and validated for the structural behavior of two plates,connectedby a bolt,under a variety of loads and elevated temperatures.The method consists of a global-scale model thatsimulates the structure(here the two plates)by volume finite elements,and in which the bolt is modelled bya spring.The spring properties are provided by a smallscale model,in which the bolt is modelled by volumeelements,and for which the boundary conditions are retrieved from the global-scale model.To ensure the small-scale model to be as computationally efficient as possible,simplifications are discussed regarding the materialmodel and the modelling of the threads.For the latter,this leads to the experimentally validated application ofa non-threaded shank with its stress area.It is shown that a non-linear elastic spring is needed for the bolt inthe global-scale model,so the post-peak behavior of the structure can be described efficiently.All types of boltedconnection failure as given by design standards are simulated by the twoscale method,which is successfullyvalidated(except for net section failure)by experiments,and verified by a detailed system model,which modelsthe structure in full detail.The sensitivity to the size of the part of the plate used in the small-scale modelis also studied.Finally,multi-directional load cases,also for elevated temperatures,are studied with the two-scale method and verified with the detailed system model.As a result,a computationally efficient finite elementmodelling approach is provided for all possible combined load actions(except for nut thread failure and netsection failure)and temperatures.The two-scale method is shown to be insightful,for it contains a functionalseparation of scales,revealing their relationships,and consequently,local small-scale non-convergence can behandled.Not presented in this paper,but the two-scale method can be used in e.g.

关 键 词：Two-scale method Finite element model Bolted connection Structural failure Elevated temperatures FIRE 

分 类 号：O24[理学—计算数学]