【摘要】：基于光彈試驗(yàn)分析立方體陣列在一個(gè)分級(jí)加卸載周期下力鏈和顆粒位移的演化過程,結(jié)果表明,接觸力和顆粒位移在卸載階段均存在殘留,且接觸力和顆粒位移的演化特征一致表明,卸載過程中存在一個(gè)臨界荷載值。通過建立主力鏈顆粒的串聯(lián)接觸模型,得出殘留接觸力取決于力鏈所受側(cè)向摩阻力,包括顆粒間接觸摩擦與咬合力。結(jié)合光彈條紋解析所得特征顆粒所受接觸力,分析加卸載作用下主力鏈所受摩阻力的演化特征,得出加卸載過程中主力鏈所受摩阻力與外荷載呈正相關(guān),表明隨著外荷載的增大,顆粒體系的內(nèi)摩擦作用逐漸發(fā)揮以抵抗外力;但相同外荷載下,加載和卸載階段主力鏈所受摩阻力并不相等,是立方體陣列產(chǎn)生殘留接觸力的根源。
[Abstract]:Based on photoelastic experiments, the evolution process of force chain and particle displacement of cubic array under a staged loading and unloading period is analyzed. The results show that both contact force and particle displacement are residual in unloading stage. The evolutional characteristics of contact force and particle displacement show that there is a critical load value in the unloading process. By establishing the series contact model of the main chain particles, it is concluded that the residual contact force depends on the lateral friction resistance of the chain, including the contact friction and bite force between the particles. Combined with the contact force of the characteristic particles obtained by photoelastic stripe analysis, the evolution characteristics of the friction resistance of the main chain under the action of loading and unloading are analyzed, and the positive correlation between the friction resistance of the main chain and the external load during the loading and unloading process is obtained. It is shown that with the increase of the external load, the internal friction of the particle system gradually exerts itself to resist the external force, but under the same external load, the frictional resistance of the main chain in the loading and unloading stages is not equal, which is the root of the residual contact force produced by the cube array.
【作者單位】： 同濟(jì)大學(xué)道路與交通工程教育部重點(diǎn)實(shí)驗(yàn)室;
【基金】：國家自然科學(xué)基金資助項(xiàng)目(41472247,51608384)~~
【分類號(hào)】：TU45
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本文編號(hào)：2156787