IV. TEST PROCEDURE 



Electrical resistance type of strain gages were used to measure 

 the strains produced by the external pressure applied to the hemispherical 

 model. Detailed information on the various types of gages used are given 

 in Table 1. Rectangular rosettes of the gages were installed on the concave 

 and convex side of the head in a manner so that for any particular rosette, 

 a corresponding rosette was located on the opposite surface on a radial 

 line drawn from the center of curvature of the concave surface, A row of 

 rosettes was installed across theiam^ridian,. 6* = ° , with the f orientation 

 as given in Figure 3, and at 6 = 90® in order to ascertain the degree of 

 symmetrical response of the vessel. 



Figure 5 shows the strain gages being installed by Mr. E. J. Winkler, 

 a technician in the Structural Research Department. The complete strain 

 gage instalJiationsiiDir Configuration A, on the concave and convex surfaces 

 are shown in Figures 6 and 7, respectively. The complete strain gage 

 installations for Configuration B on the concave and convex surfaces are 

 shown in Figures 8 and 9, respectively. Two of the seal plugs for the cable 

 penetrations are shown in place in the close-up view (Fig. 10). The wires 

 to the gages on the convex surfaces were brought through the vessel in three 

 Gonax fiittings (Fig. 6). 



