Stress Analysis Toolkit
The strength of adhesively bonded joints is a complex non-linear function of material properties and geometry. The precise nature of failure for adhesively bonded joints and how to calculate failure strength has for some time been a subject of debate amongst researchers in this field. The ability to predict strength, however, is central to the design function in order to eliminate costly development exercises.
This analysis module has been written to provide a designer with a means of assessing the stresses and strains occurring within tubular joints under torsional or axial loading. It is suggested that by combining the strains calculated with a maximum strain failure criterion, a reasonable estimate of strength can be obtained. The module should be considered as a design aid to be used in conjunction with appropriate considerations relating to surface treatments, process and materials control. Inelastic adhesive properties are taken into account together with profiled geometry and thermal stresses.
Particular attention has been paid to making the module quick and easy to use interactively because it is recognised that design is an iterative process and that analysis of this type is more useful if it can give a rapid and flexible feedback.
The joint can be split into a number of steps. At the start, middle and end of each step you must define the geometry of the section by specifying the inner radius of the outer adherend and the thicknesses of the inner and outer adherends and the adhesive. A quadratic fit is made between the values specified for the start, middle and end of each step so a tapering or profiled adhesive or adherend thickness can be specified by appropriate selection of the values. The start values for a step can differ to those for the end values for the preceding step so allowing abrupt changes in section. Up to 6 steps may be defined.
Below are some examples of joints that can be analysed.
