Investigation of strain in plates made from glass-reinforced plastic and subjected to tension

Abstract

b id i rec t iona l g l a s s r e i n f o r c e d plas t ic , with two d i r e c t ions of the r e in fo rc ing (with a 1:1 s t ruc ture) , when the pla tes a r e subjected to uniaxial tension. The spec imens (plates) for the expe r imen t s were cut out of a sheet of g l a s s r e i n f o r c e d p las t ic with the th ickness 2h = 1 ram. The sheets were manufac tured by the winding method. The f i l l e r was No. 10 g lass f iber of nonalkaline composit ion, and EFB-4 r e s i n was used. The spec imens were 50 mm wide and 260 m m long. Specimens without a hole and with a cen t ra l c i r c u l a r hole 10 m m in d i ame te r were tested. The spec imens were s t re tched in a TsDM-10 m a chine with a constant r a t e of loading equal to 143 N / s e c , and in a TsD-5 machine with a constant s t ra in r a t e equal to 5 ram/rain . The u l t imate s t rength of the g l a s s r e i n f o r c e d p l a s t ic, de te rmined f rom the fa i lu re of a plane spec imen without a hole, was 500 MN/m ~. Strain at va r ious points of the spec imen was e s t i mated f rom the magnitude of t e m p e r a t u r e var ia t ion during act ive loading. T e m p e r a t u r e var ia t ion was m e a s u r e d with cons tan tan-copper mie ro the rmocoup le s . Thei r locat ion is shown in Fig. 1, where 1, 2, 3, and 4 a r e the points of a t tachment of the thermoeouples . Number 5 is the compensat ing the rmocouple and 6 is the m e a s u r i n g ins t rument . The tes t r e s u l t s a r e p r e sen t ed in Figs. 2 and 3. In Fig. 2 we have shown t e m p e r a t u r e var ia t ion at va r ious points of the sur face of pla tes made f rom g l a s s r e i n -