Low Impact Velocity Modeling of 3D Printed Spatially Graded Elastomeric Lattices.

Additive manufacturing technologies have facilitated the construction of intricate geometries, which otherwise would be an extenuating task to accomplish by using traditional processes. Particularly, this work addresses the manufacturing, testing, and modeling of thermoplastic polyurethane (TPU) lattices. Here, a discussion of different unit cells found in the literature is presented, along with the based materials used by other authors and the tests performed in diverse studies, from which a necessity to improve the dynamic modeling of polymeric lattices was identified.

Influence of foam thickness on the control of EMG activity during a step-down task in females.

Compliant foams can be used to mitigate ground reaction forces. However, it is unknown how foam surfaces influence the modulation of leg muscle activity. Thus, the current study aimed to investigate how the neuromuscular system managed changes in expected loading due to various thickness of foam placed on the landing surface during a step down task.

Impact properties of thiol-ene networks.

In this study, a series of thiol-ene networks having glass transition temperatures ranging from -30 to 60 °C were synthesized utilizing several multifunctional thiols and two trifunctional alkenes. Thermomechanical properties were determined using dynamic mechanical analysis, and impact properties were determined using pendulum impact and drop impact testing protocols. The impact behavior was found to directly correlate to the glass transition temperature, except when the temperature at which the impact event occurs overlaps with the range of temperatures corresponding to the viscoelastic dissipation regime of the polymer.