CAJ | 학술논문

利用摆锤冲击加载SHPB试验装置，通过改变摆锤锤头的形状和控制锤头的冲击速度，以获得较为理想的加载波形，进行岩石动态压缩试验和动态巴西盘试验，测试砂岩试样的动态抗压强度和抗拉强度，并分析砂岩试样的抗压和抗拉强度随摆锤锤头冲击速度的变化规律。动态抗压强度试验过程中岩样破裂时的应变率为100～102/s，这是人们通常认为的中应变率范围，动态巴西盘试验时试样中心拉应力所对应的加载速率为100～400 GPa/s。测得砂岩试样的动态抗压和抗拉强度都随着摆锤冲击速度的增大而增大，表现出一定的应变率相关性。巴西盘试样最终沿着加载直径方向破坏成两半，但是试样和入射杆、透射杆接触面处的“V”字型破坏区随着冲击速度的增大而趋于明显。摆锤冲击加载的优势在于能够直接获得岩石分离式霍普金森压杆(SHPB)试验所需的理想的入射波形，该装置为测试中应变率条件下岩石的强度和破裂过程提供了一种试验手段。
이용파추충격가재SHPB시험장치，통과개변파추추두적형상화공제추두적충격속도，이획득교위이상적가재파형，진행암석동태압축시험화동태파서반시험，측시사암시양적동태항압강도화항랍강도，병분석사암시양적항압화항랍강도수파추추두충격속도적변화규률。동태항압강도시험과정중암양파렬시적응변솔위100～102/s，저시인문통상인위적중응변솔범위，동태파서반시험시시양중심랍응력소대응적가재속솔위100～400 GPa/s。측득사암시양적동태항압화항랍강도도수착파추충격속도적증대이증대，표현출일정적응변솔상관성。파서반시양최종연착가재직경방향파배성량반，단시시양화입사간、투사간접촉면처적“V”자형파배구수착충격속도적증대이추우명현。파추충격가재적우세재우능구직접획득암석분리식곽보금삼압간(SHPB)시험소수적이상적입사파형，해장치위측시중응변솔조건하암석적강도화파렬과정제공료일충시험수단。
By using the pendulum hammer driven SHPB apparatus,the ideal incident waveform is generated by changing the shape and by controlling the impact velocity of the pendulum hammer. The compressive test and Brazilian test of sandstone specimens were conducted using the pendulum hammer driven split Hopkinson pressure bar(SHPB) apparatus,and the variation of dynamic compressive strength and dynamic tensile strength under different impact velocity of the pendulum hammer is examined. The strain rate ranging from 100/s to 102/s, which is generally considered as intermediate strain rate,is measured during the dynamic compression test,and the loading rate corresponding to the tensile stress at center of rock disc,ranging from 100 GPa/s to 400 GPa/s, are generated during the dynamic Brazilian test. The dynamic compressive strength and dynamic tensile strength of the sandstone samples increase with the impact velocity,showing an obvious strain-rate dependency. During the dynamic Brazilian test the sandstone samples were finally separated into two halves along the loading diameter. The V-shaped failure zone at the contact area between the incident and transmitted bars and the rock specimen becomes larger with the increasing impact velocity. The advantage of the pendulum hammer driven SHPB apparatus is that the ideal incident stress waveform can be excited by the pendulum hammer,and it can supply a feasible experimental method to measure the dynamic strength and failure process of the rock under the intermediate strain rate.