Probability Calibration Of Load Duration Modification Factor For Timber Roofs In The Polish Mountain Zones

Archives of civil engineering

T. Doma?ski Institute of Building Materials and Structures, Cracow University of Technology, PolandEmailOther articles by this author:De Gruyter OnlineGoogle Scholar¹ 

[1] Institute of Building Materials and Structures, Cracow University of Technology, Poland

关键词: Keywords: reliability;    snow wind loads;    timber structures;   

DOI  :  10.2478/ace-2014-0013

学科分类：建筑学

来源: Polska Akademia Nauk * Instytut Podstawowych Problemow Techniki / Polish Academy of Sciences, Institute of Fundamental Technological Research

【 摘 要 】

The resistance parameters of timber structures decrease with time. It depends on the type of load and timber classes. Strength reduction effects, referred to as creep-rupture effects, due to long term loading at high stress ratio levels are known for many materials. Timber materials are highly affected by this reduction in strength with duration of load. Characteristic values of load duration and load duration factors are calibrated by means of using probabilistic methods. Three damage accumulation models are considered, that is Gerhard [1] model, Barret, Foschi[2] and Foshi Yao [3] models. The reliability is estimated by means of using representative short- and long-term limit states. Time variant reliability aspects are taken into account using a simple representative limit state with time variant strength and simulation of whole life time load processes. The parameters in these models are fitted by the Maximum Likelihood Methods using the data relevant for Polish structural timber. Based on Polish snow data over 45 years from mountain zone in: Zakopane – Tatra, Świeradów – Karkonosze, Lesko – Bieszczady, the snow load process parameters have been estimated. The reliability is evaluated using representative short – and long –term limit states, load duration factor kmod is obtained using the probabilistic model.

【 授权许可】

Unknown