It has been a while, but don’t worry, my students have been giving me plenty of blank stares in the meantime. Seriously, I am teaching a course this semester called Design of Machine Elements which I consider a key opportunity for students to bridge their engineering knowledge toward their upcoming professional career. Given the course is an elective, I have opted to not give exams, but instead assign regular engineering project problems. We discuss fasteners, bonding, shafts, gears, springs, etc. and discuss critical implications of fit, tolerancing, and perhaps most importantly the different means of engineering communication. At the heart of every single problem, are load and deformation analyses. These analyses are much easier for well characterized, isotropic materials (e.g. steel, aluminum, cast iron), but become much more intensive as we change to a highly engineered, anisotropic material such as a carbon fiber reinforced epoxy.
Advanced Bike Tech
Carbon fiber frames are lightweight, but how light is too light? It requires a lot of engineering to make sure your frame is light and strong.
So we left off last time discussing anisotropy; specifically how a composite tube may differ from a metal tube. We have defined anisotropy as having different properties or responses in different directions. It would be helpful if anisotropy were easy to visualize, but it is not. Go perform an image search using “anisotropic material” and you may expect to see some nice images of anisotropy . However, the search yields many images that when thought about and combined in various ways allow us to develop an understanding of anisotropy, but none clearly show anisotropy.
We at Pursuit believe that an expert is not someone who knows all the answers, but instead knows the right questions to ask. As noted below, I definitely do not know all the answers surrounding composites and it is our hope that through this Tech portion of the Pursuit Blog that we are able to investigate and discuss some of the pertinent questions. In particular, we will focus on design, modeling, and manufacturing of composites as related to bicycle frames. Below is the first step in that direction, where some of main hurdles of composite usage are discussed. Finally, each Tech post will include credible references (a tip of the hat to Nate Silver ) so that readers may delve further into the topics addressed should they wish to do so.