An evaluation of the influence of manufacturing methods on interlocked aluminium-thermoplastic composite joint performance

Joining techniques for multi-material structures are critical for increased use of lightweight materials such as aluminium alloys and thermoplastic composites in the automotive industry. Interlocking adhesive joints (IAJs) can provide increased mechanical performance over standard adhesive joints, but manufacturing methods suitable for industrial applications must be developed. Here, three methods are examined for fabricating composite adherends with recessed macroscale features. The methods differ in the way the fabric material is draped over a mould and are referred to as “simple stacking”, “moulding-in”, and “fibre-cutting”. The IAJs are tested under quasi-static, 0.5 m/s and 3 m/s loading rates and the fibre-cutting method achieves the best mechanical performance. One reason is that it gives a homogenous fibre distribution across the overlap width, providing good flexural properties at the recessed features. It also results in resin-rich regions along the overlap length, which lead to beneficial “snubbing” for improved interlocking, and progressive, energy-absorbing failure. The fibre-cutting method is simple to automate and well-suited for scale-up to industrial manufacturin

თამაზ თამაზაშვილი

თამაზ თამაზაშვილი - გენერალ-მაიორი, საქართველოს შსს კახეთის სამხარეო მთავარი სამმართველოს უფროსი (1996-2001), შსს საგზაო პოლიციის მთავარი სამმართველოს უფროსის მოადგილე (2001

Trends in the Reproductive Phenology of two Great Lakes Fishes

<p>To assess potential effects of climate change on Great Lakes fish populations, we evaluated trends in the reproductive phenology of Yellow Perch <i>Perca flavescens</i> (spring spawner) and Lake Trout <i>Salvelinus namaycush</i> (autumn spawner). For Yellow Perch in Lake Michigan, the estimated reproductive midpoint date (50% of mature females ripe or spent, 50% not yet spawned) took place 6.2 d/decade earlier in the spring near Milwaukee from 1988 to 2012 and 1.8 d/decade earlier in Green Bay from 1980 to 2012. At both locations water temperatures at the spawning sites on the midpoint date showed no trends, but mean water temperatures during the spring at the spawning site and midlake increased over the study period. This suggests that Yellow Perch spawning areas were warming sooner in the spring and that Yellow Perch were spawning earlier to maintain a consistent spawning temperature. Lake Trout phenological patterns were more complex. For Lake Trout in Lake Michigan near Milwaukee, there was a marginally significant trend for spawning to take place 2.1 d/decade later in the autumn from 1983 to 2006. However, water temperatures at the spawning site at the midpoint date did not change and autumn temperatures at the site and at midlake did not show a warming trend. For Lake Trout in Lake Superior near the Apostle Islands, the midpoint date did not change from 1988 to 2012. Water temperatures at the spawning site on the midpoint date and during the autumn also showed no trends, but midlake summer and autumn water temperatures increased significantly. Overall, Yellow Perch in Lake Michigan have shifted reproductive timing in a manner consistent with a warming climate, but the relationship of climate change to reproductive phenology remains unclear for Lake Trout in Lake Michigan and Lake Superior.</p> <p>Received December 15, 2014; accepted August 7, 2015</p