tailieunhanh - Failure Analysis Case Studies II Episode 2

Tham khảo tài liệu 'failure analysis case studies ii episode 2', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 23 Table 1 m N note g29 frame bolts yield rotation about toes 945 hinge in panel frame bolts yield rotation about heels 2571 hinge in angle leg 3344 frame and panel too. Other modes only apply to large areas for instance failure by fracture of frame bolts obviously does not apply to areas which do not include the connection between adjacent frames. The table shows that the bolted connections between the frames are weak by comparison with the frames themselves whereas the bending moment capacity of the composite panels is about the same as the capacity of the bolted connections. This suggests that the capacity of the wall to resist pressure is limited either by the frame bolts or by the strength of the composite panels between the frames. 6. GLOBAL STRENGTH OF SEGMENTS OF FIREWALL The wall can be thought of as a sequence of right-angled triangular segments alternately base up and base down each segment corresponding to one of the triangles of the N-form truss. The base of each triangle is bolted or welded to the ceiling or the floor and the other two sides are clamped to a vertical or a diagonal of the truss. The triangles are almost identical although not precisely so because the relation between the layout of the frames and the layout of the truss varies between segments. If we neglect that variation each triangular segment can be treated as part of an infinite plate between parallel abutments supported to form the infinite sequence of right-angled triangular segments sketched in Fig. 3. Under a uniform pressure loading extended over the whole plate each segment will deform identically and symmetry then imposes some conditions of the deformation. If w x y is the deflection of triangular segment 1 in Fig. 3 w x b y is the deflection of segment 0 w a X b y is the deflection of segment 2 and so on. Symmetry and continuity impose additional conditions on the derivatives on the boundaries for instance on the vertical boundary between segment 2 and segment 3 w 0 y - wA.