GB/T 21239-2022Test method for compression after impact properties of fiber reinforced plastic laminates (English PDF)

Foreword

This document is in accordance with the provisions of GB/T 1.1-2020 "Guidelines for Standardization Work Part 1: Structure and Drafting Rules of Standardization Documents" drafted.

This document replaces GB/T 21239-2007 "Test method for compression performance of fiber-reinforced plastic laminates after impact", and Compared with GB/T 21239-2007, in addition to structural adjustment and editorial changes, the main technical changes are as follows.

a) Added the content and calculation method of "effective compressive modulus after impact" and "ultimate compressive strain after impact" (see Chapter 1, 9.2 and 9.3);

b) Two definitions of "conditional impact energy" and "impact energy cut-off value" have been added (see Chapter 3);

c) increased the thickness of the arbitration specimen (see 5.2);

d) Other layup methods of laminates have been changed (see 5.3.3, 5.3.3 of the 2007 edition);

e) The requirements for non-destructive testing of laminates are added (see 5.4);

f) Added the content of "Conditional Impact Energy" (see 6.2.2);

g) The provisions of three measuring instruments, micrometer, caliper and depth gauge, have been added (see 7.2.2~7.2.4);

h) Added the provisions when the impact damage size is too large (see 8.5);

i) The provisions for the assembly of the specimen and the compression fixture have been added (see 8.7);

j) The requirements for the alignment of specimen installations have been added (see 8.8);

k) Added provisions for applying initial load, unloading, and strain gauge zeroing and balancing (see 8.9);

l) Added provisions for fixing lateral plates and sliding plates (see 8.10);

m) the operation of checking the strain values of the four strain gages has been changed (see 8.11, 8.7 of the 2007 edition);

n) Added "Test Validity Judgment Method" (see 8.13).

1 Scope

This document specifies the method, principle, sample, test conditions, test equipment, test Test procedures, result calculations and test reports.

This document applies to the post-impact compressive strength, post-impact effective compression of continuous fibre-reinforced plastic laminates with balanced symmetrical plies Determination of modulus and ultimate compressive strain after impact.

2 Normative references

The contents of the following documents constitute essential provisions of this document through normative references in the text. Among them, dated citations documents, only the version corresponding to that date applies to this document; for undated references, the latest edition (including all amendments) applies to this document.

GB/T 1446 General Principles of Test Methods for the Properties of Fiber Reinforced Plastics

GB/T 3961 Terminology of Fiber Reinforced Plastics

3 Terms, Definitions and Symbols

4 Principles of the method

After the sample is impacted with a certain energy at the center of the sample along the thickness direction, a compressive load is applied to the sample along the length direction until the sample is […]