麦克唐纳飞行器公司（McDonnell Aircraft Corporation），是一家美国航空航天制造企业，总部设在密苏里州圣路易斯附近。
A software tool called ELIFE has been developed which will predict the fatigue life of solder joints, component leads, and plated through holes. ELIFE is also capable of identifying the critical components which require analysis, greatly simplifying life predictions. The results of complex finite element analyses of printed circuit assemblies are an integral part of the software, but are transparent to the user. Experimental tests have been used to improve the accuracy of ELIFE. Thermal, mechanical, and dynamic test results were used to obtain material properties previously unavailable. Test results were also used to validate the analytical models
The active vertical tail (AVT) successfully reduced the buffet response of structures by utilizing piezoelectric actuators, strain gauge sensors, and simple control techniques. The AVT is a 5%-scale aeroelastically tailored structure that exhibits vibration response similar to a full-scale aircraft structure, and was designed such that it's piezoelectric actuators could provide control authority in the first two bending modes. The AVT was wind-tunnel tested on a generic twin-tailed double-delta fighter model at angles of attack and dynamic pressures representative of actual aircraft flight envelopes. At high angles of attack, the model's leading-edge vortices impinge upon the AVT. Simple control algorithms were used with piezoelectric actuators and collocated strain gauge sensors to either minimize the acceleration at the AVT's tip or the strain at the root of the tail. Control gains were verified to be a nonlinear function of angle of attack, dynamic pressure, and location of the actuator/sensor pair. Spectral analysis showed that the peak response of the controlled AVT was up to 65% lower than the uncontrolled response. This represents approximately an order of magnitude improvement in the fatigue life of a similar aircraft structure. The rms response below 200 Hz was reduced by over 20%.
AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
