Accelerating vs Constant Rate of Insertion in Wood Dowel Welding

Abstract

Dowel insertion rates whether accelerating or constant are determining parameters for the tensile strength of welded dowel joints. Dowel insertion at acceleration up to 4–7 m/s2 appears to yield the best results at the lower dowel insertion speed, characteristic of welding by manual drills. Strength results for dowel welded joints of 24 mm depths of up to 2700 N/mm2 have been obtained. Constant dowel insertion rates appear instead to yield best results when the insertion rate is much higher and can be better controlled, as it is the case for a computer controlled dowel insertion equipment. Strength results for dowel welded joints of 24 mm depths of up to 4700 N/mm2 have been obtained for insertion rates of 18–20 mm/s and welding time as short as 1.2 s. The results indicate that at low to medium insertion rates, the greater is the acceleration the better are the results. At fast insertion rates the acceleration has only little effect. The predominant effect is that a short welding time yields a high strength joint.