The Johns Hopkins University

Vanessa D Alphonse

Morgana M Trexler

Zhiyong Xia

Steven M Storck

Andrew C Merkle

Matthew G Bevan

Evan P Lloyd

Catherine M Carneal

Jeffrey M Paulson

Quang T Luong

Mark A Athey

Kathleen M Perrino

A system provided herein may be configured to evaluate helmet performance. The system may include an impact assembly that includes a stationary post operably coupled to one or more stationary load cells and a plurality of modular headforms. Each modular headform may include a first side and a second side configured to lock together around the impact assembly and receive a helmet. The modular headform may determine a position of the helmet relative to the one or more stationary load cells. Furthermore, the one or more stationary load cells may be configured to measure impact force at a position where one of the plurality of the modular headforms are operably coupled to the impact assembly. Additionally, each of the plurality of modular headforms correspond to a position in relation to the impact assembly to measure the impact force to the one or more load cells at a predefined number of impact locations on the helmet to evaluate the performance of the helmet.

System and method for evaluation of helmet performance

Strain sensing compositions including a polymeric matrix material and a mechanophore component distributed throughout the polymeric material and covalently bonded to the polymeric material are provided. The mechanophore component undergoes a visible color change and the strain sensing composition exhibits a continuous three-dimensional (3D) spatial strain distribution including at least one color gradient upon direct or indirect impact by an object. Methods of forming strain sensing compositions are also provided. Methods of evaluating a strain distribution associated with an impact of a surrogate material comprising a mechanophore component are also provided.

Strain sensing compositions

Growing community of inventors

Silver Spring, MD, United States of America

Vanessa D Alphonse