This paper is concerned with the tensile properties of auto-body plastics at wide strain rates ranging from 0.001/sec to 100/sec. Plastic is utilized as a structural material due to their lightweight and good formability. Auto-body structure experiences various strain rates under crash condition. Material properties of auto-body plastic are important due to their strain rate sensitivity.

Tensile test of plastic usually results in non-uniform deformation at gauge section of a specimen. This characteristic disturbs obtaining accurate material properties. Force equilibrium grid method (FEGM) is a solution which compensates non-uniform deformation problem. This method has some difficulty to utilize due to its complex procedure. Digital image correlation (DIC) method is simple and accurate strain measuring procedure which compensates the difficulty. High speed tensile test is conducted for obtaining material properties of auto-body plastic. DIC method and FEGM is utilized for measurement of strain.

Key words: High speed tensile test(고속인장시험), Strain rate sensitivity(변형률속도 민감도), Auto-body plastics(자동차용 플라스틱), DIC method(디지털 이미지 연관 기법), Force equilibrium grid method(하중평형 격자법)