Gives a method of determining certain tensile properties of textile glass reinforced plastics which is not necessarily suitable for materials of very high tensile strength, but applies to reinforced thermosetting resins and reinforced thermoplastics. Determines the initial tangent modulus of elasticity and the tensile secant modules of elasticity and maximum tensile stress.

1.1 This European Standard specifies a method of determining certain tensile properties of textile glass reinforced plastics. The method specified is not necessarily applicable to materials of very high tensile strength, for example unidirectional reinforced materials¹⁾. The method is applicable to reinforced thermosetting resins and also to reinforced thermoplastics.

Injection-moulded test specimens made from reinforced thermoplastics are subject to fibre orientation, and may give values that are untypically high; however, they may be used if other methods of specimen preparation are impracticable.

1.2 The method describes the determination of the following tensile properties:

• the initial tangent modulus of elasticity and the tensile secant modulus of elasticity (when it is not possible to determine the initial tangent modulus of elasticity, the tensile secant modulus of elasticity at 0.1 % strain is determined);

• maximum tensile stress;

NOTE If there is a clean break the maximum tensile stress is the stress at break; in other cases it is the stress corresponding to the maximum force.

• the elongation at maximum force and, possibly, the elongation at break.

The force-elongation curves at different temperatures, degrees of humidity and rates of strain yield interesting information concerning the behaviour of the materials.

1.3 It is only possible to obtain comparable values between different materials if identical test specimens are used. These should also be tested under well defined conditions of pretreatment, temperature, humidity and rate of strain.

Finally, it is the aim of this method to obtain tensile results that can be used either for

• quality control, or

• the preparation of specifications for materials.