發(fā)布時間：2018-01-20 21:59

  本文關(guān)鍵詞： 橋梁工程 鋼橋面板 數(shù)值斷裂力學(xué) 疲勞裂紋 耦合擴展機理 擴展有限元法　出處：《中國公路學(xué)報》2017年03期 　論文類型：期刊論文

【摘要】：為研究鋼橋面板疲勞裂紋耦合擴展機理,建立焊接分析有限元模型,對縱肋-頂板連接細節(jié)、縱肋-橫隔板連接細節(jié)的焊接全過程進行數(shù)值模擬,基于擴展有限元方法建立鋼橋面板數(shù)值斷裂力學(xué)模型,對疲勞敏感細節(jié)裂紋靜、動態(tài)擴展行為進行分析。焊接過程分析結(jié)果表明:縱肋-頂板連接焊縫區(qū)域、縱肋-橫隔板焊縫端部區(qū)域均存在較大的殘余拉應(yīng)力,峰值接近鋼材屈服強度;橫隔板挖孔邊緣存在切向殘余拉應(yīng)力,峰值約為200 MPa。疲勞裂紋擴展行為分析結(jié)果表明:縱肋-頂板連接細節(jié)在車輛荷載單獨作用下以受壓為主,考慮殘余應(yīng)力場作用后細節(jié)處于拉-拉應(yīng)力狀態(tài),疲勞裂紋為Ⅰ型主導(dǎo)的Ⅰ-Ⅱ-Ⅲ型復(fù)合裂紋;車輛偏載作用下縱肋產(chǎn)生扭轉(zhuǎn)變形,計入殘余應(yīng)力后縱肋-橫隔板連接焊縫焊趾受拉開裂,萌生于縱肋焊趾、向縱肋腹板擴展的疲勞裂紋為Ⅰ型主導(dǎo)的Ⅰ-Ⅱ-Ⅲ型復(fù)合裂紋,萌生于縱肋-橫隔板連接焊縫橫隔板側(cè)焊趾和橫隔板挖孔邊緣的疲勞裂紋為Ⅰ-Ⅱ型復(fù)合裂紋;縱肋對接細節(jié)的疲勞裂紋為Ⅰ型裂紋,車輛荷載作用下以受拉為主,位于縱肋底板弧形過渡區(qū)的裂紋相較于縱肋底板中間區(qū)域具備更強的擴展能力。
[Abstract]:In order to study the mechanism of fatigue crack coupling propagation of steel bridge panel, the finite element model of welding analysis was established, and the welding process of longitudinal rib-roof connection detail and longitudinal rib-transverse diaphragm connection detail was simulated numerically. Based on the extended finite element method, the numerical fracture mechanics model of steel bridge slab is established, and the static and dynamic propagation behavior of fatigue sensitive crack is analyzed. The welding process analysis results show that: longitudinal rib-roof joint weld zone. The residual tensile stress exists in the end of the weld seam of longitudinal rib-transverse partition plate, and the peak value is close to the yield strength of steel. There is tangential residual tensile stress at the edge of the cut hole of the transverse diaphragm, the peak value is about 200 MPA. The results of fatigue crack growth analysis show that the longitudinal rib-roof connection details are mainly under the action of vehicle load alone. After considering the residual stress field, the detail is in the state of tensile and tensile stress, and the fatigue crack is mode 鈪，

本文編號：1449543