@techreport{oai:jaxa.repo.nii.ac.jp:00043828, author = {大竹, 邦彦 and 遠藤, 修司 and 種村, 利春 and OOTAKE, Kunihiko and ENDO, Shuji and TANEMURA, Toshiharu}, month = {Aug}, note = {Poisson's ratio is one of the most important factors that have the effect on the ac- curacy of the stress analysis of the solid propellant grain. It is often assumed, however, that the propellant is incompressible. Therefore Poisson's ratio takes the value of one half, especially at low strain levels. In the present investigation, Poisson's ratio is evaluated experimentally by the photographic method. In the experiment, a special care is paid for the size and the marking of the test specimens. The errors of the measurement by the photographic method may be mainly raised from the following two ; one depends on the projecting machine employed, and the other depeneds on the sharpness of the marks. The former is of inevitable nature. The latter is caused by the roughness of the propellant's surface, which is scarcely seen in rubber specimens. These errors can be canceled out by taking the average values. The experiment is conducted at the room temperature and at the strain rate of 0.03 mm/mm/min. The strains were calculated in accordance with the formula which defines the natural strains. Test results show that Poisson's ratio of the propellant has a value of 0.47+0.01 at the strain level up to 10%, and then the ratio decreases gradually because of the dewetting phenomena., 資料番号: NALTM0245000, レポート番号: NAL TM-245}, title = {コンポジット固体ロケット推進薬のポアソン比測定}, year = {1973} }