class: center, middle, inverse, title-slide .title[ # Lecture 10 ] .subtitle[ ## Streching and Bending ] .author[ ### Dr. Christopher Kenaley ] .institute[ ### Boston College ] .date[ ### 2024/2/15 ] --- class: inverse, top # Material Properies of the Dead, Toughness, and Resilience <!-- Add icon library --> <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/5.14.0/css/all.min.css"> .pull-left[ Today we'll .... - Learn simple methods to assess stiffnesses - MP3 headstart ]  ] --- class: top # Bending + In bending, load is compressive and tensile at the same time. + Need a new model, not simply stress vs. strain .center[  ] --- class: top # Bending How much a beem will deform under a stress is given by the flexural stiffness (*M*): $$ M=EI $$ + `\(E\)` is the Young's modulus + `\(I\)` is the second moment area, which is essentially the distribution of that stiffness (i.e., area) For a beam under a symmetrical bending load, the deflection is given by: `$$d=\frac{Fl^3}{3EI}$$` .center[ <img src="img/bendstress.jpg" alt="drawing" width="200"/> ] --- class: top # Bending We'll be bending wood (in lab--signup link coming!!) + How do changes in *I* effect *M*? .center[ <img src="img/wood.png" alt="drawing" width="400"/> <br> Two orientations of the wood stirrer. <br> ] --- class: top # Bending We'll be bending wood, both wet and dry. + How does strain (deformation) rate effect *M*? .center[ <img src="img/viscorate.png" alt="drawing" width="400"/> ] --- class: top # Instestine: Simple tensile tests We'll be stretching pig intestine. + What is the stiffness of the intestine in longitudinal and axial loading? .center[ <img src="img/tensiletest.jpeg" alt="drawing" width="400"/> ] --- class: top # Instestine: Simple tensile tests We'll be stretching pig intestine (on your own). + Is this material anisostropic? .center[ <img src="img/anis.jpeg" alt="drawing" width="400"/> ] --- class: center, middle # Thanks! Slides created via the R package [**xaringan**](https://github.com/yihui/xaringan).