Calculation and Analysis on Out-Plane Force of Hollow-Shearwall in Large Space Residence

For new large space plate-wall structure, the out-of-plane problems of shearwall caused by vertical loads cannot be ignored. The out-of-plane stiffness can be increased by introducing Hollow-shearwall. However, currently rare attention has been focused upon research on the out-of-plane problems of hollow-shearwall. Based on the theory of elastic thin plate，the hollow-shearwall is regarded as an orthotropic plate in this paper. According to the actual situation of the loading on the shearwall, it is the first time that the analytic solution of the hollow-shearwall with different boundary constraints under the combined action of the end moment and vertical pressure has been derived in this paper. The numerical results by the program developed with Mathematical based on the analytic solution are compared with those obtained with ANSYS and it shows that this method is correct and reliable. Under various operating conditions, it is easy to apply this program for the out-of-plane force analysis, which can provide reference for the further research on the out-of-plane capacity and a reliable basis for engineering design.

Analysis of Power Boiler Furnace Wall and Its Supporting Structure

In this paper, wall tube stresses of power boiler furnace according to three different design options of furnace wall stiffening system were investigated. As the loading condition, furnace design gas pressure, fluid pressure inside the wall tube and the temperature difference between furnace wall and reaction plate were used. When the simplest design option is applied, wall tube stress levels are unsatisfactory. Furnace design gas pressure has strong influences on wall tube stress in this case. The second option using a reaction plate successfully decreased stresses on furnace wall tubes. However, another problem has arisen from using the reaction plate between furnace wall and wall stiffening H-beam called buckstay. When there are temperature differences between furnace wall and reaction plate, wall tubes are subjected to a large compression load. As final design option, the wall stiffening system using a space plate in addition to the reaction plate was analyzed. The space plate on reaction plate gives room to absorb differential thermal expansion between furnace wall and reaction plate, and satisfactory stress results on furnace wall tubes were obtained.

XIX. The Croonian lecture - Observations on the locomotor system of echinodermata

1. Holothuria.— When a longitudinal incision is made through the perisome of a Holothurian ( Holothuria communis ) there is generally seen escaping, along with the branches of the respiratory tree and genital gland, a long sacculated tube filled with a fluid, and holding in suspension a large quantity of a brick-dust coloured pigment. This tube, which may be one-and-a-half times the length of the entire animal, and from one line to half-an-inch in diameter, is the polian vesicle (Plate 79, fig. 1, a ). On following it upwards it is found to open freely into a wide circular canal (Plate 7 9, fig. 1, b ) a short distance from the termination of the stone canal. From this circular canal five lozenge-shaped sinuses (Plate 79, fig. 1, c ) project forwards, and from each of these two large oval sinuses (Plate 79, fig. 1, d ) run forwards parallel with each other, the ten oval sinuses becoming continuous with the hollow stems of the tentacles (Plate 79, fig. 1, e ). In a Holothurian 8 inches in length, exclusive of the tentacles, the lozenge-shaped sinuses, which may be designated the sinuses of the circular canal, measure a quarter of an inch from above downwards and a little more from side to side. From around the pointed upper ends of the canal sinuses the five longitudinal muscular bands take their origin. When a solution of Berlin blue is injected into the polian vesicle, the circular canal and its sinuses, the oval sinuses and tentacles, the radial canals, pedicels and ampullæ are rapidly distended; but, unless the pressure be kept up for a considerable time, none of the coloured fluid penetrates into the stone canal, and either the vesicle, ring, or one of the sinuses gives way before it reaches the madreporic plate. If one of the radial canals be divided while the injection is being proceeded with, the coloured fluid at once escapes, and the tension within the polian vesicle, the circular canal, and the tentacles is diminished. If plaster of Paris be substituted for the solution of Berlin blue, a cast is readily obtained of the circular canal and its sinuses, but the plaster does not find its way either into the sinuses of the tentacles or into the radial canals. When, however, a coloured solution of gelatine is forced into the polian vesicle, the tentacles and their sinuses, the radial canals, ampullæ, and pedicels are filled, as well as the circular canal and its sinuses. Examination of specimens injected with plaster of Paris and gelatine shows the circular canal to be a quarter of an inch in diameter, and to communicate freely both with the polian vesicle and with the lozenge-shaped sinuses springing from it. The specimens injected with a gelatine mass further show that each canal sinus opens into a cæcal tube, which runs forward internal to the sinuses of the tentacles as far as a wide circum-oral space (Plate 79, fig. 2, a ). This space communicates by well-defined apertures (Plate 79, fig. 3, b ), with that portion of the body cavity which lies between the sinuses and the œsophagus, and which is reached through the circular apertures between the sinuses of the circular canal (Plate 79, fig. 1, f ).