【摘要】：基于傳遞矩陣方法,提出了一種在高溫下對含多條裂紋簡支鋼梁進(jìn)行模態(tài)分析的方法。在模態(tài)分析過程中,用無質(zhì)量的扭轉(zhuǎn)彈簧來等效橫向裂紋,推導(dǎo)出每條裂紋產(chǎn)生的局部柔度;通過材料力學(xué)參數(shù)的變化引入溫度模塊,考慮溫度變化在簡支梁截面產(chǎn)生的軸向載荷的影響,推導(dǎo)出含溫度參數(shù)、裂紋條數(shù)和裂紋幾何參數(shù)的整條裂紋梁傳遞矩陣。根據(jù)簡支梁的邊界條件,求解出不同溫度下含多條裂紋簡支鋼梁的固有頻率。結(jié)果表明:簡支梁橫截面上的軸向溫度載荷對固有頻率的影響非常大,不能忽略不計(jì);溫度的升高會顯著減小裂紋簡支鋼梁的各階固有頻率;隨著裂紋相對深度的增大,裂紋簡支鋼梁第一階固有頻率和臨界溫度均逐漸降低。
[Abstract]:Based on the transfer matrix method, a modal analysis method for simply supported steel beams with multiple cracks at high temperature is proposed. In the process of modal analysis, a massless torsional spring is used to equivalent the transverse crack, and the local flexibility of each crack is derived. By introducing the temperature module into the material mechanics parameters and considering the influence of temperature change on the axial load of the simply supported beam, the transfer matrix of the whole cracked beam with temperature parameters, crack number and crack geometry parameters is derived. According to the boundary conditions of simply supported beams, the natural frequencies of simply supported steel beams with multiple cracks at different temperatures are calculated. The results show that the axial temperature load on the cross section of simply supported beam has a great influence on the natural frequency and can not be ignored, and the increase of temperature can significantly reduce the natural frequencies of simply supported steel beams with cracks. With the increase of the relative depth of cracks, the first natural frequency and critical temperature of simply supported steel beams with cracks decrease gradually.
【作者單位】： 南京航空航天大學(xué)機(jī)械結(jié)構(gòu)力學(xué)及控制國家重點(diǎn)實(shí)驗(yàn)室;
【基金】：江蘇高校優(yōu)勢學(xué)科建設(shè)工程基金(PAPD)
【分類號】：TG142.1
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本文編號：2337647