tailieunhanh - design of wood aircraft structures phần 10

"Làm thế nào tôi tạo nên Cánh quạt gỗ" của Al Schubert, Phần 1 Phần 2 Phân tích đơn giản hóa Wing căng thẳng Tia bài viết phân tích tốt về xây dựng spars so với spars gỗ rắn. ( PDF) Sức mạnh của yếu tố máy bay kim loại | L L L L L Figure 4 4 2. Protection against splitting. Figure 4 43. Tapering of face plates. L L L L L Figure 4 44 Drainage diagram of wing direct method. L L L L L 1 2 Inch holes drilled at the low point of the lowest compartments - Figure 4 4 - Drainage diagram of wing internal method. 218 L L L L L Ỉ L L L Service experience indicates that drainage holes for individual compartments should be not less than one-quarter inch in diameter with three-eighths inch being preferable. Drainage holes to the exterior used with the internal drainage system should probably be somewhat larger. If the internal drainage system is used it is suggested that the inter-compartment drainage holes be inspected after the internal finish has been applied to make sure that the finish has not clogged the internal drain holes. This will necessitate attaching the top skin last. Drain holes are usually drilled from the external surface so that the splintering does not mar the external finish. After drilling drain holes all splinters should be carefully removed from the inner surface and the edges of the holes should be sanded lightly and protected by the application of several coats of spar varnish. It is common practice in order to avoid damage to structural members by the drill to drill drainage holes an appreciable distance from the low corner of a compartment. This practice must be avoided and some method of insuring proper location of drain holes at the actual low points must be developed by the aircraft manufacturer that will not only prevent damage to the framework but .will also provide complete drainage of the structure. It is therefore recommended that proof of the adequacy of the drainage system chosen be demonstrated by setting up the structure with the top cover removed in a position corresponding to its attitude when the airplane is resting on the ground. Water is then poured into the structure and the actual performance of the drainage system observed. Careful design to prevent