ISO 15310 pdf download.Fibre-reinforced plastic composites — Determination of the in-plane shear modulus by the plate twist method
1 Scope
1.1 This International Standard specifies a method for determining the in-plane shear modulus (G 1 2 ) of fibre- reinforced plastic composites using a standard plate specimen. When applied to isotropic materials, the shear modulus measured is independent of direction. 1.2 The method is used to determine the shear modulus of the test specimens but not to determine the shear strength. It applies to a plate supported on two points on one diagonal and loaded on the other diagonal by the simultaneous movement of two loading points attached to a cross-beam. 1.3 The method is suitable for use with fibre-reinforced plastic composites with both thermoset and thermoplastic matrices. Due to the shear deformation being applied under flexural conditions, for laminated materials with different fibre formats and/or different orientations, the layers of material must be well distributed across the section so that it is approximately “homogeneous” in the through-thickness direction. The principal material axes, if present, must be orientated normal to the plate edges (see 3.8). NOTE This method can be applied to unreinforced polymers and other materials (e.g. metals, ceramics and metal- or ceramic-matrix composites). For material fabricated using unidirectional plies, the shear modulus obtained using a multidirectional specimen (i.e. 0°/90°/45°) is not the same as that obtained for unidirectional or cross-ply (0°/90°) material. 1.4 The method is performed using specimens which may be moulded to the chosen dimensions, machined from test plates or machined from flat areas of products.1.5 The method specifies preferred dimensions for the specimen. Tests which are carried out on specimens of other dimensions, or on specimens which are prepared under different conditions, may produce results which are not comparable. Other factors, such as the speed of testing and the conditioning of the specimens, can influence the results. Consequently, when comparative data are required, these factors must be carefully controlled and recorded. NOTE The stress-strain response in shear is very non-linear at higher strain levels. This test method determines the modulus within a low strain region and is not applicable to higher strains.
2 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of this International Standard. For dated references, subsequent amendments to, or revisions of, these publications do not apply. However, parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies. Members of ISO and IEC maintain registers of currently valid International Standards.ISO 291 :1 997, Plastics — Standard atmospheres for conditioning and testing. ISO 1 268:1 974 1 ) , Plastics — Preparation of glass fibre reinforced, resin bonded, low-pressure laminated plates or panels for test purposes. ISO 2602:1 980, Statistical interpretation of test results — Estimation of the mean — Confidence interval. ISO 281 8:1 994, Plastics — Preparation of test specimens by machining. ISO 5893:1 993, Rubber and plastics test equipment — Tensile, flexural and compression types (constant rate of traverse) — Description.
3 Definitions
For the purposes of this International Standard, the following definitions apply. 3.1 plate deflection w the distance over which the loading points move relative to the support points (see Figure 2), expressed in mm NOTE The plate deflection is normally taken from the movement of the rigid cross-beam carrying the two loading points. 3.2 modulus of elasticity in shear in-plane shear modulus G 1 2 <isotropic materials> the shear modulus, expressed in GPa, in a direction other than that of the reinforcement, measured between plate deflections of 0,1 h and 0,3h, where h is the plate thickness (see 3.7) 3.3 speed of testing the rate of movement of the loading points relative to the support points, expressed in mm/min 3.4 span S the mean of the distance S 1 between the two support points and the distance S 2 between the two loading points (see Figure 3), expressed in mm