基于深海底质流变特性和接地比压的集矿机牵引力计算方法

Traction force calculation method for mining vehicle based on rheological performance of deep-sea sediment and grounding pressure of crawler

作为深海采矿水力提升系统的重要组成部分,履带式集矿机的牵引力及行走性能对深海资源的安全高效开采具有重要影响。目前,深海履带式集矿机牵引力的计算仅考虑深海底质的弹塑性,尚未考虑与时间相依的流变特性以及履带式集矿机作业时履带底部的不同接地比压(受沟壑、障碍、斜坡影响)等情形。本文通过深海模拟底质直剪流变和压-剪耦合流变的本构理论与试验研究,建立了基于不同的深海底质本构模型(弹塑性、直剪流变、压-剪耦合流变)和接地比压分布(均布、线性分布、非均布)下履带式集矿机牵引力计算模型;利用功能原理推导了相应的履带式集矿机牵引力计算公式,并分析了深海底质本构模型、接地比压分布、履齿个数对履带式集矿机牵引力的影响规律,为履带式集矿机直行、转弯和越障等稳定性与通过性评估提供科学依据。研究结果表明:采用直剪流变和弹塑性本构模型时,线性递增与线性递减接地比压分布对应的牵引力数量级大于均匀分布与正弦分布情况,线性递增与线性递减下的牵引力比均匀分布与正弦分布对履带板数目变化更为明显;深海底质本构模型对履带式集矿机牵引力的影响比接地比压分布类型更大。采用模拟土压-剪耦合流变本构模型计算得到的深海履带式集矿机所需牵引力为最大、流变沉陷也最大,更接近深海采矿工程实际。

The tracked mining vehicle's walking performance has a great influence on the efficiency of exploiting deep-sea resources as an important part of the hydro-mechanics lifting deep-sea mining system.Currently,the calculation of mining vehicle traction force only considers the elastic-plastic performance of deep-sea sediment instead of its time-dependent mechanical performance(the more obvious rheological performance than land soil)and different grounding pressure distributions(influenced by a deep-sea mountain,ditch)under the crawler of mining vehicle.This paper mainly obtained a compression-shear coupling rheological constitutive model based on the experimental and theoretical analyses of deep-sea simulant sediment,and then established traction force model based on different constitutive models(rheological models and elastic-plastic model)and different grounding pressure distributions(uniformed,linear and sine types).Based on the above,the corresponding traction force models was deduced by work-energy principle and then the influence of traction force was analyzed by considering the different constitutive models of deep-sea sediment and different grounding pressure distributions.The study can provide scientific foundation for stability and trafficability when straight walking,turning and crossing obstacles of tracked mining vehicle.The results show that the magnitude of require traction force under the linear increment and decrement grounding pressure distributions are greater than the one under the uniformed and sine grounding pressure distributions when adopting direct shear rheological model and elastic-plastic model.Moreover,the traction forces vary more obviously under the increment and decrement grounding pressure distributions than those under the uniformed and sine grounding pressure distributions.The influence of the constitutive models is more obvious than that of grounding pressure on the traction force of mining vehicle.The required traction force and sinkage under the compression-shear coupling rheological constitutive mode are the maximum among the different constitutive models and more close to practical deep-sea mining engineering.