岩石力学与工程学报
巖石力學與工程學報
암석역학여공정학보
CHINESE JOURNAL OF ROCK MECHANICS AND ENGINEERING
2014年
8期
1662-1671
,共10页
金解放%李夕兵%邱灿%陶伟%周学进
金解放%李夕兵%邱燦%陶偉%週學進
금해방%리석병%구찬%도위%주학진
岩石力学%循环冲击%静载荷%损伤累积%演化模型
巖石力學%循環遲擊%靜載荷%損傷纍積%縯化模型
암석역학%순배충격%정재하%손상루적%연화모형
rock mechanics%cyclic impact%static loads%damage accumulation%evolution model
为系统、深入探索静载荷与循环冲击组合作用下岩石疲劳力学性能及其影响因素,研究建立岩石损伤累积演化模型,并探索静载荷对岩石损伤累积的影响。基于静载荷与循环冲击组合作用下岩石损伤累积演化具有“快速上升→平缓发展→急速上升”的趋势,并与S型曲线进行对比,将Logistic函数进行逆变换,建立静载荷与循环冲击作用下岩石损伤累积演化的数学模型。将模型中3个参数值固定,变化另一参数值的大小,分析所得损伤曲线簇的变化规律,确定损伤演化模型中参数的物理意义。基于最小二乘逼近理论,建立损伤模型拟合的目标函数,通过在Matlab中编写拟合程序,得到损伤模型的拟合方法。最后用试验数据验证模型的正确性。利用损伤模型拟合不同静载荷下岩石循环冲击的损伤试验结果,分析模型中参数与静载荷间的关系,研究静载荷的大小对岩石损伤累积演化的影响。结果表明,该损伤模型理论依据充分,关系式简单,参数物理意义明确,能表征静载荷与循环冲击组合作用下岩石损伤累积演化的初始阶段、低速阶段和加速阶段,能体现出轴压和围压对岩石损伤累积演化的影响。围压和轴压的大小影响岩石疲劳损伤的演化趋势,围压越大,轴压大小的变化对参数α,β和η的影响越小;无论轴压大小如何变化,围压大小的变化始终影响岩石损伤累积演化趋势。
為繫統、深入探索靜載荷與循環遲擊組閤作用下巖石疲勞力學性能及其影響因素,研究建立巖石損傷纍積縯化模型,併探索靜載荷對巖石損傷纍積的影響。基于靜載荷與循環遲擊組閤作用下巖石損傷纍積縯化具有“快速上升→平緩髮展→急速上升”的趨勢,併與S型麯線進行對比,將Logistic函數進行逆變換,建立靜載荷與循環遲擊作用下巖石損傷纍積縯化的數學模型。將模型中3箇參數值固定,變化另一參數值的大小,分析所得損傷麯線簇的變化規律,確定損傷縯化模型中參數的物理意義。基于最小二乘逼近理論,建立損傷模型擬閤的目標函數,通過在Matlab中編寫擬閤程序,得到損傷模型的擬閤方法。最後用試驗數據驗證模型的正確性。利用損傷模型擬閤不同靜載荷下巖石循環遲擊的損傷試驗結果,分析模型中參數與靜載荷間的關繫,研究靜載荷的大小對巖石損傷纍積縯化的影響。結果錶明,該損傷模型理論依據充分,關繫式簡單,參數物理意義明確,能錶徵靜載荷與循環遲擊組閤作用下巖石損傷纍積縯化的初始階段、低速階段和加速階段,能體現齣軸壓和圍壓對巖石損傷纍積縯化的影響。圍壓和軸壓的大小影響巖石疲勞損傷的縯化趨勢,圍壓越大,軸壓大小的變化對參數α,β和η的影響越小;無論軸壓大小如何變化,圍壓大小的變化始終影響巖石損傷纍積縯化趨勢。
위계통、심입탐색정재하여순배충격조합작용하암석피로역학성능급기영향인소,연구건립암석손상루적연화모형,병탐색정재하대암석손상루적적영향。기우정재하여순배충격조합작용하암석손상루적연화구유“쾌속상승→평완발전→급속상승”적추세,병여S형곡선진행대비,장Logistic함수진행역변환,건립정재하여순배충격작용하암석손상루적연화적수학모형。장모형중3개삼수치고정,변화령일삼수치적대소,분석소득손상곡선족적변화규률,학정손상연화모형중삼수적물리의의。기우최소이승핍근이론,건립손상모형의합적목표함수,통과재Matlab중편사의합정서,득도손상모형적의합방법。최후용시험수거험증모형적정학성。이용손상모형의합불동정재하하암석순배충격적손상시험결과,분석모형중삼수여정재하간적관계,연구정재하적대소대암석손상루적연화적영향。결과표명,해손상모형이론의거충분,관계식간단,삼수물리의의명학,능표정정재하여순배충격조합작용하암석손상루적연화적초시계단、저속계단화가속계단,능체현출축압화위압대암석손상루적연화적영향。위압화축압적대소영향암석피로손상적연화추세,위압월대,축압대소적변화대삼수α,β화η적영향월소;무론축압대소여하변화,위압대소적변화시종영향암석손상루적연화추세。
In order to explore the fatigue properties and its influence factors,an evolution model of damage accumulation was established and the effect of static loading on the damage accumulation of rock under cyclic impaction was studied. Compared with the S-shaped growth curve,a model of the damage evolution of rock having a trend of rapid rising,steady development and sharp rising subjected to the coupled static-cyclic impact loadings was established using the inverse transformation of logistic function. The physical meanings of the parameters in the damage accumulation model were determined by analyzing the variation of the curves with three parameters fixed and one varying. The objective function for fitting the damage model was established based on the approximation theory of the least squares. After programmed with Matlab,the data fitting of the damage accumulation model was calculated and the damage accumulation model was proved to be correct by the test data. The evolution model of damage accumulation was used to fit the experimental data of rock damage upon cyclic impaction under different static loadings. The effect of static loading on damage accumulation was studied through analyzing the relation between the fitting parameters and the static loadings. The axial pressure and the confining pressure have great effect on the trend of dynamic fatigue damage of rock. The change of axial pressure has smaller influence on the parametersα,βandη with the confining pressure increasing. The change of confining pressure always influences evolution the trend of dynamic damage accumulation no matter how much the value of the axial compression is.