@techreport{oai:jaxa.repo.nii.ac.jp:00044839, author = {藤沢, 良昭 and 池田, 為治 and 祖父江, 靖 and 宮地, 敏雄 and 小河, 昭紀 and FUJISAWA, Yoshiaki and IKEDA, Tameharu and SOFUE, Yasushi and MIYACHI, Toshio and OGAWA, Akinori}, month = {Sep}, note = {Models of hollow blades were made and tested to prove the applicability of hollow blades as fan rotor blades for the turbo-fan engine. The hollow blade models were fabricated by the diffusion bonding of two plates which were made of a titanium alloy. One of the plates had three spanwise stiffeners and the other was a constant thickness plate. By this method, the models were completed to a satisfactory accuracy of shape and size. No defect could be found in the diffusion bonded areas by an ultrasonic detector. The models had uniform cross sections of 80mm chord length, 4mm maximum thickness and 1mm skin thickness. The hollowness rate of the cross section was about 27%. The length of the model was 300mm. Tests on the bending stiffness, the torsional stiffness and the bending fatigue properties of the model were carried out and the following results were obtained. 1)The bending stiffness and torsional stiffness of the hollow blade model were reduced to about 90% of the value of the solid blade model. Experimental results of the bending and torsional stiffness properties compare closely to the theoretically predicted results. 2)The mode of fatigue failure of the models which were tested with cyclic bending was, without exception, a chordwise crack which originated from the outer surface of the model. The relation between the cyclic maximum bending stress and life of the model was nealy the same as the σ-N relation of the model material. No separation could be detected in the bonded areas after the test. According to the above-mentioned results, it can be said that properly designed hollow blades of this type will have satisfactory stiffness and strength as fan rotor blade for the turbo-fan engine and will be effective for reducing the weight of the engine., 資料番号: NALTR0585000, レポート番号: NAL TR-585}, title = {拡散接合構造ファン中空翼の強度試験}, year = {1979} }