5.1 This test method is designed for both wood and metal bonded specimens.5.2 The test method provides a means to compare flexural properties between assemblies.5.3 The data are reduced to a comparable basis by means of the formulas given in 11.1 and 11.2. It is recognized that these formulas do not apply rigidly to tests made in the manner described in this method, but serve only to reduce the data to a comparable basis.1.1 This test method covers the determination of the comparative properties of either metal or wood adhesive bonded assemblies when subjected to flexural stresses with standard shape specimens and under defined conditions of pretreatment, temperature, relative humidity, and testing technique. The test specimen and testing technique were designed to develop a large portion of shear forces between the laminae of the test piece when the load is applied, rather than to reduce shear stress to a minimum as is done in other ASTM test methods for flexural properties. This method is not applicable to assemblies made with nonrigid adherends. The data obtained are not suitable for design work.1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information purposes.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

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4.1 This test method is useful in that the joint configuration closely simulates the actual joint configuration of many bonded assemblies. Surface preparation of the adherends can affect the apparent shear strength of the adhesive and can be one of the variables under study.4.2 This test method is also useful as an in-process quality control test for laminated assemblies. In practice the laminated assembly is either made over size and test specimens removed from it or a percentage of the assemblies are destructively tested.4.3 The misuse of strength values obtained from this test method as design allowable stress values for structural joints could lead to product failure, property damage, and human injury. The apparent shear strength of an adhesive obtained from a given small single-lap specimen may differ from that obtained from a joint made with different adherends or by a different bonding process. The normal variation of temperature and moisture in the service environment causes the adherends and the adhesive to swell and shrink. The adherends and adhesive are likely to have different thermal and moisture coefficients of expansion.4.3.1 Even in small specimens, short-term environmental changes can induce internal stresses or chemical changes in the adhesive that permanently affect the apparent strength and other mechanical properties of the adhesive. The problem of predicting joint behavior in a changing environment is even more difficult if a different type of adherend is used in a larger structural joint than was used in the small specimen.4.4 The apparent shear strength measured with a single-lap specimen is not suitable for determining design allowable stresses for designing structural joints that differ in any manner from the joints tested without thorough analysis and understanding of the joint and adhesive behaviors.4.5 Single-lap tests may be used for comparing and selecting adhesives or bonding processes for susceptibility to fatigue and environmental changes, but such comparisons must be made with great caution since different adhesives may respond differently in different joints. Review Guide D4896 for further discussion of concepts for interpretation of adhesive-bonded single-lap joint data.1.1 This test method (Note 1) is intended for determining the comparative shear strengths of adhesives in large area joints when tested on a standard single-lap-joint specimen and under specified conditions of preparation and testing. Adhesives respond differently in small versus large area joints (Note 2).NOTE 1: While this test method is intended for use in metal-to-metal applications, it may be used for measuring the shear properties of adhesives using plastic adherends, provided consideration is given to the thickness and rigidity of the plastic adherends. Doublers or bonded tabs may be required for plastic adherends to prevent bearing failure in the adherends.NOTE 2: This variation can be influenced by adhesive density, flow characteristics, cure rate, gel time, carrier composition, entrapped volatiles, volatiles released during cure, etc. and also by cure cycle variables including: temperature, time, pressure, rise rate to temperature, cool-down rate, etc. In addition to the processing variables joint size changes the level of constraint on the adhesive as well as the influence of induced tensile loads at the edge of the joint during mechanical or thermal loading.1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

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4.1 Tests conducted in accordance with this practice are used to evaluate the stability of laminated glazing materials when they are exposed outdoors or used indoors. The relative durability of glazing in outdoor use can be very different depending on the location of the exposure because of differences in ultraviolet (UV) radiation, time of wetness, temperature, pollutants, and other factors. It cannot be assumed, therefore, that results from one exposure in a single location will be useful for determining relative durability in a different location. When comparing exposure results, at a minimum, the locations of exposure are to be as similar as possible with regard to critical factors such as the amount and rate of solar radiation deposited on the specimens, temperature and humidity levels during exposure. Exposures in several locations with different climates that represent a broad range of anticipated service conditions may be necessary.4.2 Because of year-to-year climatological variations, results from a single exposure test cannot be used to predict the absolute rate at which a material degrades. Several years of repeat exposures are needed to get an average test result for a given location.4.3 The results of short-term natural and accelerated exposure tests can provide an indication of relative outdoor performance, but they should not be used to predict the absolute long-term performance of a material. The results of tests conducted under natural exposure for less than twelve months will depend on the particular season of the year in which they begin.1.1 This practice is intended to cover procedures for the exposure of laminated glass materials to natural and accelerated weather.1.2 This practice is limited to the method by which the material is to be exposed and the general procedure to be followed. It is intended for use with finished articles of commerce as well as with all sizes and shapes of test specimens.1.3 Means of evaluation of the effects of weathering will depend on the intended use for the test material.1.4 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard.1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

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