Split Hopkinson Pressure Bar is an apparatus that is used to study materials behavior under high speed deformation, where strain rate is very high. Hopkinson bars are usually custom made based on the needs of customers, who are mostly researchers in universities or research labs. In this work, the authors designed a small size split Hopkinson pressure bar. The objectives of this project are 1) to design a well-structured Hopkinson bar by means of solid mechanics fundamentals 2) to implement finite element simulation to verify the design. The designed Split Hopkinson bar consists of two metallic bars with a specimen placing in between, a striker assembly, an air compressor, instrumentation and a data acquisition system. The solid model of the apparatus is built using CAD software SolidWorks. The design is validated by extensive finite element simulation using ABAQUS. A working prototype is physically built and tested. High speed deformation experiments are developed using the prototype fabricated. The experiments are conducted as an impact is made by the striker on one of the bars, which generates stress wave through the specimen and the other bar. During the experiments, strain in specimen is determined by measuring strains on the bars using strain gauges mounted on the bars. Preliminary tests demonstrate that the performance of the apparatus is as predicted by the FEM simulation. This work is supported by an NSF’s CMMI (Civil, Mechanical and Manufacturing Innovation) program.

Experimental and Finite Element methods are used for investigating the effect of cyclic thermal loading on the clamp load decay in preloaded single-lap bolted joints that are made of dissimilar-materials. Joint material combinations include steel and lightweight materials such as aluminum and magnesium alloys, with various different thicknesses. The range of cyclic temperature profile varies between −20°C and +150°C. A computer-controlled environmental chamber is used for generating the desired cyclic temperature profile and duration. Real time clamp load data is collected using high-temperature load cells. Percent clamp load decay is investigated for various combinations of joint materials, initial preload level, and test specimen thicknesses. Thermal and material creep finite element analysis is performed using temperature-dependent mechanical properties. FEA result has provided insight into interesting experimental observations regarding model predictions and the experimental data is discussed.

Eastern Shore (UMES) on a research project on modeling and simulation of wind turbines for structural health monitoring purposes. Mr. Dyab received his Undergraduate Degree with Honors in Engineering with a Mechanical Engineering Specialization from the University of Maryland Eastern Shore (UMES) in December 2012. For his senior design project, Mr. Dyab designed and fabricated a working prototype of a small-size Hopkinson Pressure Split Bar for material properties characterization under high speed deformation. During the undergraduate studies, Mr. Dyab worked as a team leader for AIRSPACES Project (Air-propelled Instrumented Robotic Sensory Platform(s) for Assateague Coastline Environmental Studies) at UMES from 2010 to 2012.

Eastern Shore with a degree in Engineering with a mechanical engineering specialization. During his senior undergraduate year, Mr. Diab along with a group of undergraduates, designed and built an autonomous boat to monitor water quality variables in lakes and estuaries.