【摘要】：伴隨著建筑鋼結(jié)構(gòu)的巨大發(fā)展，鋼結(jié)構(gòu)厚板經(jīng)常應(yīng)用在高層、大跨建筑，，橋梁，海洋平臺(tái)，壓力容器及船體結(jié)構(gòu)中。隨著鋼板厚度及焊縫尺寸增加，承受荷載更加復(fù)雜，拘束作用更加突出，以及局部地區(qū)頻繁出現(xiàn)低溫，鋼結(jié)構(gòu)厚板發(fā)生Z向破壞的可能性也越來(lái)越大。本文對(duì)鋼厚板裂紋受厚度方向荷載時(shí)的斷裂韌性進(jìn)行了有限元分析，對(duì)鋼結(jié)構(gòu)厚板及其連接焊縫的Z向性能進(jìn)行了實(shí)驗(yàn)研究，最后提出基于強(qiáng)度和韌性指標(biāo)的Z向性能鋼材選材及設(shè)計(jì)方法。主要成果如下： （1）對(duì)幾種典型的厚板及其連接內(nèi)裂紋進(jìn)行有限元模擬，對(duì)裂紋分布、共生裂紋間距、鋼板厚度等加以考慮，分析斷裂參數(shù)K、J的變化規(guī)律，為實(shí)際中厚板的斷裂分析提供參考。 （2）針對(duì)Q345B鋼材60~165mm幾種不同厚度的鋼板，對(duì)其母材和十字形焊接連接熱影響區(qū)，以及對(duì)接連接進(jìn)行取樣。取樣類型分為沿軋制方向（X向）和厚度方向（Z向），并在-60℃~20℃下進(jìn)行簡(jiǎn)單拉伸試驗(yàn)，得到屈服、極限強(qiáng)度f(wàn)_y、f_u及斷面收縮率Z隨板厚、焊縫尺寸、取樣類型及溫度等的變化規(guī)律。 （3）針對(duì)Q345B鋼材60~165mm幾種不同厚度的鋼板，對(duì)其母材和十字形焊接連接熱影響區(qū)，以及對(duì)接連接進(jìn)行取樣。取樣類型分為沿軋制方向（X向）和厚度方向（Z向），并在-60℃~20℃下進(jìn)行夏比V形缺口沖擊試驗(yàn)，得到?jīng)_擊功Akv隨板厚、焊縫尺寸、取樣類型及溫度等的變化規(guī)律。 （4）針對(duì)Q345B鋼材60~165mm幾種不同厚度的鋼板，對(duì)其母材和十字形焊接連接熱影響區(qū)進(jìn)行取樣。取樣類型分為沿軋制方向（X向）和厚度方向（Z向），并在-60℃~20℃下進(jìn)行三點(diǎn)彎斷裂試驗(yàn)，得到斷裂韌性指標(biāo)CTOD值隨板厚、焊縫尺寸、取樣類型及溫度等的變化規(guī)律。 （5）在試驗(yàn)基礎(chǔ)上，針對(duì)現(xiàn)有規(guī)范的結(jié)構(gòu)Z向性能敏感性評(píng)價(jià)標(biāo)準(zhǔn)，修正和補(bǔ)充了基于拉伸力學(xué)性能的評(píng)價(jià)方法，并增加了基于沖擊和斷裂韌性的評(píng)價(jià)方法�？紤]了溫度的影響作用，并針對(duì)不同板厚提出具體的敏感指標(biāo)確定建議。
[Abstract]:With the great development of building steel structures, steel thick plates are often used in high-rise, large-span buildings, bridges, offshore platforms, pressure vessels and hull structures. With the increase of steel plate thickness and weld size, the load is more complex, the restraint effect is more prominent, and the low temperature occurs frequently in the local area, the possibility of Z-direction failure of thick plate of steel structure is more and more large. In this paper, the fracture toughness of thick steel plate under the load of thickness direction is analyzed by finite element method, and the Z-direction behavior of thick plate and joint weld of steel structure is studied experimentally. Finally, the material selection and design method of Z direction performance steel based on strength and toughness index are put forward. The main results are as follows: (1) several typical thick plates and their internal cracks are simulated by finite element method. The distribution of cracks, the spacing of symbiotic cracks and the thickness of steel plate are taken into account. It provides a reference for the fracture analysis of practical plate. (2) for Q345B steel 60~165mm steel plate with different thickness, the base metal, the heat affected zone of cross-welded joint and the butt connection are sampled. The sampling types are divided into the direction of rolling (X direction) and the direction of thickness (Z direction), and the simple tensile tests are carried out at -60 鈩

本文編號(hào)：2363210