ASTM D5574-94 (R2021) pdf free download.Standard Test Methods for Establishing Allowable Mechanical Properties of Wood-Bonding Adhesives for Design of Structural Joints.
1.1 These test methods cover the principles for establishing allowable mechanical properties for adhesives that can be used to design adhesive-bonded joints for structural components and assemblies of wood or wood with other materials. These test methods are modeled after Practice D245.
1 .2 The properties determined are allowable shear stress. allowable tensile stress, and allowable shear modulus.
1.3 In determination of allowable shear- and tensile-stress levels, these test methods are limited by the horizontal shear and tension perpendicular-to-the-grain capacity of the wood adherends (hard maple, Acer saccharuni, Marsh.). The adhesives so tested may actually have shear or tensile allowable stresses exceeding the wood, but the determined allowable design stress levels are limited (upper bounded) by the wood in these test methods. If a wood other than hard maple is used for testing the adhesive, then the allowable strengths are upper bounded by the properties of that particular wood.
1.4 The strength properties are determined by standard ASTM test methods. As a result, only procedural variations from the standards and special directions for applying the results are given in these test methods.
1 .5 Time-to-failure data derived from creep-rupture testing (see Test Method D4680) provide a measure of the ultimate strength of an adhesive bond as a function of time at various levels of temperature and moisture.
1.5.1 With proper caution, useful service life at a given shear stress level may be extrapolated from relatively short loading periods.
1 .6 The resistance of the adhesive to permanent loss of properties due to aging (permanence) is assessed by means of strength tests afier constant elevated-temperature and moisture aging of test specimens.
3. Terminology
3. 1 Definitions.
3. 1. 1 allowable design stress, ti—a stress to which a material can he subjected under stated service conditions with low probability of mechanical failure within the design lifetime. (D4896)
3.1.1.1 Discussion—Allowable design stress is obtained by multiplying the basic stress by a safety factor and possibly one or more modification factors as required by the intcndcd service environment.
3. 1.2 allowable shear stress, n—in an adhesive-bonded joint, the allowable design stress for structural joints subjected to shear force.
3.1.3 allowable tensile stress, n—in an adhesive-bonded joint, the allowable design stress for structural joints subjected to tension force.
3. 1.4 creep rupture, n—the fracture of a material resulting from a sustained stress (or sum of stresses) above the creep rupture limit.
3.1.4.1 Discussion—The material may experience creep through the primary, secondary, and tertiary stages of rupture.
3.1.5 creep-rupture limit, n—the stress level below which creep rupture will not occur within a given time in a specified environment. See creep rupture.
3.1.6 durability, n—as related to adhesive joints, the endurance of joint strength relative to the required service conditions. (D907)
3. 1.6. 1 Discussion—Service conditions may include water and other chemicals, temperature. stress, radiation, microorganisms, and other environmental factors.ASTM D5574 pdf download.