To ensure quality resources with usable information, I used an online database called EBSCO to do some of my resource. One source I found was the study of strength and fracture behavior of different types of carbon composites. A number of composites were studied, but I was most interested in comparing longitudinal oriented fibres with transversal oriented fibres. After looking at some graphs, I found that longitudinal-oriented fibres can bear a maximum of 2.5 kN/mm compared to approximately 0.8 kN/mm that transversal-oriented fibres can bear before breaking. The longitudinal fibres also have 23 times more fracture toughness than the transversal fibres, meaning it is far less likely to fracture if it has a crack.
I found another study that looked at the differences of fracture resistance between different types of aluminum alloys. The study found that the prefered alloy for bikes, AA6061, had an inferior response to fracture resistance compared to AA5083. However, AA6061 had a higher fracture resistance compared to a commercially pure aluminum. AA5083 is an alloy composed of the combined metals aluminum and magnesium, whereas AA6061 is composed of a mix of aluminum, magnesium, and silicon.
Photo by Mizrak 
