發(fā)布時(shí)間：2019-06-26 08:37

【摘要】：筒倉是一種用來儲存各種散體材料的筒狀構(gòu)筑物。由于其具有占地面積少、倉容量大、使用方便等優(yōu)點(diǎn),故在糧食,建筑、煤炭、水泥等行業(yè)被廣泛應(yīng)用。近幾十年來,隨著經(jīng)濟(jì)建設(shè)的發(fā)展,國內(nèi)筒倉數(shù)量越來越多。在筒倉結(jié)構(gòu)設(shè)計(jì)中,選取正確的貯料壓力值是保證筒倉安全可靠的前提�，F(xiàn)今,國內(nèi)外筒倉規(guī)范對于貯料壓力的計(jì)算都是以Janssen公式為基礎(chǔ)的,但大量事實(shí)表明利用該公式得到的結(jié)果與實(shí)際情況有較大的出路。故選取合適的方法對筒倉貯料壓力進(jìn)行深入的研究很有必要。 到目前為止,國內(nèi)外大量學(xué)者就這一問題進(jìn)行了分析和研究,但由于散體材料自身的復(fù)雜性,使得筒倉貯料壓力理論在很多地方難達(dá)到共識,從而導(dǎo)致大量的筒倉事故發(fā)生。 本文以武漢青山區(qū)“7.9”筒倉倒塌事故為背景,采用試驗(yàn)研究、理論分析和數(shù)值模擬相結(jié)合的方法,對筒倉各工況下的貯料壓力進(jìn)行研究,同時(shí)將結(jié)果運(yùn)用到事故筒倉,對其進(jìn)行事故分析,具體工作包括： 1.對筒倉進(jìn)行了模型試驗(yàn)研究,得出筒倉在靜止及卸料時(shí)的倉壁側(cè)壓力,并與規(guī)范結(jié)果進(jìn)行對比發(fā)現(xiàn)利用規(guī)范計(jì)算得到的貯料壓力值要比實(shí)際情況小。 2.在考慮筒倉內(nèi)貯料產(chǎn)生土拱效應(yīng)的基礎(chǔ)上建立了筒倉貯料壓力的計(jì)算公式；通過與試驗(yàn)數(shù)據(jù)及模擬結(jié)果對比,驗(yàn)證了該公式的正確性。 3.采用離散元軟件對筒倉靜止及卸料時(shí)的貯料壓力進(jìn)行了模擬,得到了筒倉在各工況下的壓力分布規(guī)律,同時(shí)分析了各個(gè)參數(shù)對側(cè)壓力的影響。 4.通過觀察筒倉卸料時(shí)顆粒的流動,得出貯料在卸料時(shí)由于流型轉(zhuǎn)變而產(chǎn)生的散體拱是造成卸料超壓的主要原因,同時(shí)由于貯料流動時(shí)的結(jié)拱-破拱導(dǎo)致筒倉卸料時(shí)倉壁側(cè)壓力會不斷的上下波動。 5.對筒倉卸料時(shí)的模擬發(fā)現(xiàn)當(dāng)筒倉孔球徑比達(dá)到6.0左右是會出現(xiàn)閉塞現(xiàn)象,同時(shí)內(nèi)摩擦系數(shù)越大越易發(fā)生卸料閉塞。 6.將離散元模擬與有限元分析相結(jié)合能很好的對筒倉進(jìn)行結(jié)構(gòu)研究,這樣得出的結(jié)果將比以往分析方法更加精確,能為今后的筒倉設(shè)計(jì)提供新的思路。
[Abstract]:Silo is a cylindrical structure used to store all kinds of bulk materials. Because of its small area, large warehouse capacity, easy to use and other advantages, it is widely used in grain, construction, coal, cement and other industries. In recent decades, with the development of economic construction, the number of silos in China is increasing. In the structural design of silo, selecting the correct storage pressure value is the premise to ensure the safety and reliability of silo. Nowadays, the calculation of storage pressure in silo code at home and abroad is based on Janssen formula, but a large number of facts show that the results obtained by this formula have a great way out with the actual situation. Therefore, it is necessary to select the appropriate method to study the silo storage pressure. Up to now, a large number of scholars at home and abroad have analyzed and studied this problem, but because of the complexity of bulk materials themselves, it is difficult to reach a consensus on silo pressure theory in many places, which leads to a large number of silo accidents. Based on the collapse accident of "7.9" silo in Qingshan District of Wuhan, this paper studies the storage pressure of silo under various working conditions by means of experimental research, theoretical analysis and numerical simulation. At the same time, the results are applied to the accident silo and the accident analysis is carried out. The concrete work includes: 1. The model test of the silo is carried out, and the side pressure of the silo wall is obtained when the silo is static and unloaded, and compared with the code results, it is found that the storage pressure calculated by the code is smaller than the actual situation. two銆，

本文編號：2506065