Investigation on Application of Dumbbell-shaped Specimen in Tensile Property Test of Nanofiber Membrane

Necking phenomenon often occurs in the tensile tests of nanofiber membrane,which will cause the deviation of the results.In order to reduce the influence of necking phenomenon,dumbbell-shaped specimen was used to modify the shape of standard rectangular strip.The results show that among the shape factors of dumbbel-shaped specimen,the impact of parallel width on breaking strength is the largest,while the impact of clamping width is the least.Proper dumbbell-shaped specimen can reduce the irregularity markedly in the tensile test of nanofiber membrane.The breaking position in the tensile test can be controlled in the middle of the sample by changing parallel length so that it can reduce the influence of stress concentration on the test result.The best modified-shape for the standard rectangular strip is that clamping width is 14-18mm,the parallel width is 8mm,the clamping length is 40mm,and the parallel length is 10mm.