ABSTRACT
B. Short-Span Specimen Geometry The basic principle behind the short-span specimen geometry is to use such a short span that crushing of the specimen occurs before any buckling of the specimen takes place. The Concora liner test (CLT) and the STFI short-span test, reported here, are examples of methods currently used in accordance with this principle. One may also refer to pioneering work by the Institute of Paper Chemistry [28] and by Ranger [59].
Concora Liner Test A frequently used method that employs a short flat specimen is the Concora liner test (CLT) designed by the Container Corporation of America [46,73]. As shown in Fig. 15, one edge of the 152 mm long specimen is clamped between two strips of metal so that a specimen free span of 6.3 mm protrudes above the clamp. A load is applied with a flat platen to the free edge of the specimen. In some cases an additional upper plate is used to reduce the influence of curl on the specimen [47,52]. The influence of height on the CLT value was investigated by the Institute of Paper Chemistry [30], and it was concluded that the CLT specimens always exhibit bending failure or edge crushing within the range of heights studied. The structural response reduces the test value below the material compression strength, limiting the effectiveness of the test.
