CAJ | 학술논문

基于瞬态动力学基本理论，选取Lycoming航空活塞发动机的普通连杆为分析对象，在通用有限元软件中建立其三维有限元模型。考虑在发动机额定转速工况下，连杆在压缩行程末期、膨胀行程初期气缸内气体压力作用下的动力学响应。分析发现：在所有载荷步下，最大等效应力和应变均出现在杆身和小头的过渡区域，且与缸内气体峰值压力同时出现；获得的最大等效应力随时间的变化曲线，可为预估连杆疲劳寿命、提高连杆疲劳可靠性提供数值依据；结合等效应力应变云图，划分出的连杆应力集中的危险区域，为修理前检测的重点区域。
기우순태동역학기본이론，선취Lycoming항공활새발동궤적보통련간위분석대상，재통용유한원연건중건립기삼유유한원모형。고필재발동궤액정전속공황하，련간재압축행정말기、팽창행정초기기항내기체압력작용하적동역학향응。분석발현：재소유재하보하，최대등효응력화응변균출현재간신화소두적과도구역，차여항내기체봉치압력동시출현；획득적최대등효응력수시간적변화곡선，가위예고련간피로수명、제고련간피로가고성제공수치의거；결합등효응력응변운도，화분출적련간응력집중적위험구역，위수리전검측적중점구역。
Based on the basic theory of transient dynamics, a general connecting rod from a Lycoming pis-ton engine had been taken as analysis object, and a three-dimensional finite element model of the rod was established in general finite element software according to initial design parameters. And then, the dynamic response of the rod to gas pressure in cylinder during final phase of compression stroke and initial phase of expansion stroke under engine’s rated speed conditions had been analyzed. Simulation results show that the maximum equivalent stress occurs at the transition zone between shaft and little head in all load steps, and with the appearance of gas peak pressure in cylinder at the same time. And the maximum equivalent stress versus time curve was obtained, which provided numerical basis for estimating fatigue life and improving fa-tigue reliability of the rod. Finally, hazardous areas of the rod had been identified according to equivalent stress and strain contours, and become the key areas of detection before repair.