可靠度論文：基于可靠度要求的木材強(qiáng)度設(shè)計(jì)值確定

1、. 可靠度論文：基于可靠度要求的木材強(qiáng)度設(shè)計(jì)值確定【中文摘要】木材強(qiáng)度設(shè)計(jì)值的準(zhǔn)確性及連接的可靠性直接影響木結(jié)構(gòu)的安全,因而需要科學(xué)合理地確定進(jìn)口規(guī)格材和層板膠合木的強(qiáng)度設(shè)計(jì)指標(biāo)及正確地評(píng)估連接的可靠性。我國木結(jié)構(gòu)設(shè)計(jì)規(guī)范GB50005-2003基于美國已有規(guī)格材的強(qiáng)度設(shè)計(jì)指標(biāo),按相同荷載作用下美國與我國木結(jié)構(gòu)設(shè)計(jì)獲得相同截面尺寸的原則,即軟轉(zhuǎn)換方法,給出了進(jìn)口北美規(guī)格材的強(qiáng)度設(shè)計(jì)指標(biāo)。正在制定的膠合木結(jié)構(gòu)技術(shù)規(guī)范實(shí)際上也按軟轉(zhuǎn)換方法給出了我國目測(cè)分等與機(jī)械彈性模量分等層板膠合木的強(qiáng)度設(shè)計(jì)指標(biāo)。本文對(duì)目前采用的軟轉(zhuǎn)換方法的可行性進(jìn)行了評(píng)估,發(fā)現(xiàn)其不足之處是認(rèn)為美國木結(jié)構(gòu)設(shè)計(jì)規(guī)范與我國規(guī)范具有相

2、同的可靠度要求。本文以進(jìn)口加拿大規(guī)格材為例,分別采用JC法與MC法驗(yàn)算了我國木結(jié)構(gòu)設(shè)計(jì)規(guī)范規(guī)定的進(jìn)口北美規(guī)格材強(qiáng)度設(shè)計(jì)值的可靠性;采用同樣的方法對(duì)目測(cè)分等與機(jī)械彈性模量分等層板膠合木的強(qiáng)度設(shè)計(jì)值進(jìn)行了驗(yàn)算。結(jié)果表明,我國木結(jié)構(gòu)設(shè)計(jì)規(guī)范及膠合木結(jié)構(gòu)技術(shù)規(guī)范給出的強(qiáng)度設(shè)計(jì)值偏高,不能滿足我國建筑結(jié)構(gòu)可靠度設(shè)計(jì)統(tǒng)一標(biāo)準(zhǔn)GB50068-2001的要求。因此有必要重新確定這類木結(jié)構(gòu)用材的強(qiáng)度設(shè)計(jì)值。本文給出了相應(yīng)的確定方法,以供修編相關(guān)規(guī)范參考。我國對(duì)于木結(jié)構(gòu)節(jié)點(diǎn)連接可靠性的研究還處于初期階段,本文給出了螺栓連接S、m及類屈服模式的功能函數(shù),然后對(duì)其可靠性進(jìn)行了評(píng)估,為木結(jié)構(gòu)節(jié)點(diǎn)連接可靠性的研究提供了參

3、考?！居⑽恼縏he accuracy of design values for wood and the reliability of connections affect the safety and reliability of timber structures. It is, therefore, necessary to specify the strength design values of imported dimension lumber and glued laminated timber and to to evaluate the reliability of co

4、nnections in a scientific and reasonable way. Based on the existing strength design values of American dimension lumber,the Code for Design of Timber Structures (GB50005-2003) specified the strength design values by using soft conversion method,which means to obtain the same cross-section size of wo

5、od member by GB50005-2003 and American National Design Specification under the same design loads. Technical code of glued laminated timber structures which is being developed uses the similar method as dimension lumber to determine the strength design values of glued laminated timber made of visuall

6、y stress-graded laminations and mechanically modulus-graded laminations. In this study, the feasibility of the soft conversion method is assessed. The results showed that the shortcoming of the current conversion method is that the U.S. standards and the Chinese code have the same reliability requir

7、ements for timber structures.In this paper, the imported Canadian dimension lumber is taken for examples, and the JC and MC method are used to evaluate the reliability of imported North American dimension lumber based on the strength design values given in the Code for Design of Timber Structures. T

8、he same methods are also used to evaluate the reliability of Glulam made of visually stress-graded laminations and mechanically modulus-graded laminations, based on the strength design values given in the Technical Code Glued Laminated Timber Structures.It is found out that the strength design value

9、s given in both codes are so large that do not satisfy the requirment of The Unified Code for Reliability Designof Building Structures GB50068-2001. It is useful to re-establish the strength design values of dimension lumber and Glulam based on the target reliability index specified in China, thus t

10、o provide reference for compiling and revising of the related codes.Study of the reliability of connections in timber structures in China is still in an early stage. In this study, the performance function of bolted connections with failure modes ofs、m andare presented, and the reliability of the co

11、nnections is evaluated . This can provide reference for future study.【關(guān)鍵詞】可靠度 規(guī)格材 層板膠合木 木結(jié)構(gòu)連接【英文關(guān)鍵詞】reliability dimension lumber glued laminated timber (Glulam) wood connection【目錄】基于可靠度要求的木材強(qiáng)度設(shè)計(jì)值確定 摘要 4-5 Abstract 5 第1章 緒論 8-24 1.1 引言 8-9 1.2 木結(jié)構(gòu)用材及連接 9-18 1.2.1 規(guī)格材 9-12 1.2.2 層板膠合木 12-15 1.2.3 木結(jié)構(gòu)的

12、連接 15-18 1.3 課題背景 18-19 1.4 國內(nèi)外相關(guān)課題研究現(xiàn)狀 19-23 1.4.1 工程結(jié)構(gòu)設(shè)計(jì)方法 19-20 1.4.2 可靠度的計(jì)算方法 20-21 1.4.3 木結(jié)構(gòu)的可靠性 21-23 1.5 本文的主要工作 23-24 第2章 可靠度理論及在木結(jié)構(gòu)中的應(yīng)用 24-38 2.1 引言 24 2.2 可靠度的基本原理 24-26 2.2.1 結(jié)構(gòu)的極限狀態(tài) 24 2.2.2 結(jié)構(gòu)的功能函數(shù) 24-25 2.2.3 結(jié)構(gòu)的可靠性與可靠指標(biāo) 25-26 2.3 可靠度的計(jì)算方法 26-30 2.3.1 JC 法 26-29 2.3.2 Monte Carlo 模擬抽樣法

13、（MC 法） 29-30 2.4 可靠度理論在木結(jié)構(gòu)中的應(yīng)用 30-36 2.4.1 木結(jié)構(gòu)的抗力與荷載分析 30-33 2.4.2 木結(jié)構(gòu)的功能函數(shù) 33-36 2.5 MATLAB 語言 36-37 2.6 小結(jié) 37-38 第3章 進(jìn)口北美規(guī)格材強(qiáng)度設(shè)計(jì)值的計(jì)算 38-61 3.1 引言 38 3.2 進(jìn)口北美規(guī)格材強(qiáng)度設(shè)計(jì)值的可靠度評(píng)估 38-42 3.3 進(jìn)口北美規(guī)格材強(qiáng)度設(shè)計(jì)值的調(diào)整建議 42-59 3.3.1 C、C、C、C 等級(jí)規(guī)格材 42-56 3.3.2 其它等級(jí)規(guī)格材 56-59 3.4 小結(jié) 59-61 第4章 層板膠合木強(qiáng)度設(shè)計(jì)值的計(jì)算 61-73 4.1 引言 61 4.2 膠合木結(jié)構(gòu)技術(shù)規(guī)范確定強(qiáng)度設(shè)計(jì)值方法的探討 61-63 4.3 層板膠合木強(qiáng)度設(shè)計(jì)值的可靠度評(píng)估 63-66 4.4 層板膠合木強(qiáng)度設(shè)計(jì)值的調(diào)整確定 66-72 4.4.1 基于最小可靠指標(biāo) 66-68 4.4.2 基于平