本文關(guān)鍵詞：焊接殘余應(yīng)力對箱型梁柱節(jié)點斷裂性能影響分析　出處：《華南理工大學(xué)》2014年碩士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： 箱型梁柱節(jié)點 焊接殘余應(yīng)力 數(shù)值模擬 斷裂分析

【摘要】：普遍認(rèn)為鋼框架結(jié)構(gòu)具有良好的抗震性能，但在1994年美國加州北嶺地震以及1995年日本阪神地震中出現(xiàn)了大量鋼框架梁柱焊接節(jié)點脆性斷裂的現(xiàn)象。按照規(guī)范設(shè)計的焊接節(jié)點并不能保證“強(qiáng)連接，弱構(gòu)件”設(shè)計思想的實現(xiàn)。焊接帶來的節(jié)點抗震性能劣化的影響不可忽視，由于計算手段的缺乏，此前大量的研究都集中在焊縫金屬性能的提升，焊接工藝的改進(jìn)以及改進(jìn)型節(jié)點的實驗，而關(guān)于節(jié)點焊接殘余應(yīng)力具體分布形態(tài)以及對節(jié)點性能影響的研究較少。 針對以上情況，，本文摸索出了利用ANSYS軟件進(jìn)行焊接過程模擬以及在焊接殘余應(yīng)力基礎(chǔ)上進(jìn)行靜力分析和斷裂分析的方法。對一T型連接件進(jìn)行了焊接過程模擬，模擬中使用熱分析與應(yīng)力分析間接耦合法和生死單元技術(shù)計算焊接溫度場和焊接殘余應(yīng)力場，采用了隨溫度變化的材料性能參數(shù)。在熱分析中討論了高斯面熱源、雙橢球體熱源、體積生熱率熱源這三種熱源的差別。最終確定體積生熱率熱源為最佳熱源，并在此基礎(chǔ)上進(jìn)行焊接殘余應(yīng)力計算，得到了焊接殘余應(yīng)力的“幾”字形分布特點以及焊縫區(qū)處于高值三軸拉應(yīng)力狀態(tài)的結(jié)論。 進(jìn)行了兩個箱型梁柱節(jié)點的性能實驗，在滯回荷載作用下，兩個節(jié)點發(fā)生了一致的焊縫斷裂現(xiàn)象，梁端未能形成塑性鉸，節(jié)點性能沒有達(dá)到抗震要求。在對T型連接件焊接過程模擬的基礎(chǔ)上，進(jìn)行了該種節(jié)點的焊接過程模擬，并且對存在焊接殘余應(yīng)力的模型進(jìn)行了滯回靜力加載和斷裂分析。分析發(fā)現(xiàn)焊接殘余應(yīng)力的存在極大提高了焊縫處各種斷裂指標(biāo)，是節(jié)點焊縫斷裂的根本原因。斷裂分析則體現(xiàn)了有無焊接殘余應(yīng)力的模型在斷裂時間的顯著差異。
[Abstract]:It is generally believed that the steel frame structure has good seismic performance. However, a large number of brittle fracture of Liang Zhu welded joints of steel frames were observed in the earthquakes in the Northern Ridge, California, USA, on 1994 and in Hanshin, Japan, on 1995. The welded joints designed according to the specifications are not guaranteed. " Strong connection. The effect of joint seismic performance deterioration caused by welding can not be ignored. Due to the lack of calculation means, a great deal of research has been focused on the improvement of weld metal performance. The improvement of welding process and the experiment of the improved joint are carried out, but there is little research on the distribution of residual stress and the effect on the performance of the joint. In view of the above situation. In this paper, the method of welding process simulation using ANSYS software and static analysis and fracture analysis based on welding residual stress are explored. The welding process of a T-joint is simulated. The welding temperature field and welding residual stress field are calculated by the indirect coupling method of thermal analysis and stress analysis and the birth and death element technique in the simulation. The difference of Gao Si surface heat source, double ellipsoid heat source and volumetric heat source is discussed in the thermal analysis. Finally, the volume heat generating rate heat source is determined as the best heat source. On the basis of the calculation of welding residual stress, the "several" zigzag distribution characteristics of welding residual stress and the conclusion that the weld zone is in the state of high value triaxial tensile stress is obtained. The performance experiments of two box beam-column joints are carried out. Under hysteretic load, the joint has a consistent weld fracture phenomenon, and the plastic hinge is not formed at the end of the beam. The performance of the joints did not meet the seismic requirements. Based on the simulation of the welding process of T-joints, the welding process of the joints was simulated. The model with welding residual stress is analyzed by hysteretic static loading and fracture analysis. It is found that the existence of welding residual stress greatly improves the fracture index of welding seam. The fracture analysis shows the significant difference in fracture time between the models with or without residual stress.
【學(xué)位授予單位】：華南理工大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2014
【分類號】：TU391;TU312.3

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本文編號：1406650