The exemplary mechanical performance and durability of ultra-high performance concrete (UHPC) has led to its rapid emergence as an advanced cementitious material. The uncharacteristically high mechanical strength and ductility of UHPC makes it a promising potential material for defense structures which may be subject to highly dynamic loads like impact or blast. However, the mechanical response...

All impact analyses performed so far for the composite plates, have treated central impacts. Furthermore, investigations on influences of the in-plane biaxial compression, tension, or tension-compression preloads on various responses of the low-velocity impact, especially the indentation, have not been performed so far. In the present research, a finite element formulation is presented for resp...

Two series of experiments are performed to investigate the dynamic response of various essential components of a class of sandwich structures, under high-rate inertial loads. One consists of dynamic inertia tests and the other involves dynamic impact tests. A split Hopkinson bar apparatus is modified and used for these experiments. First, the energy-absorbing characteristics of the plate materi...

III Abstract: This study aims at the energy absorption problems in the crash of high speed vehicles, bird impact and crashworthiness design of aircraft, and the dynamic enhancement and multi-axial behavior of honeycombs under combined shearcompression are investigated. The study consists mainly of two parts. The first part is related to the dynamic strength enhancement of honeycombs under uniax...

STUDY DESIGN The impact of various levels of mental processing and pacing (during lifting) on spine loading was monitored under laboratory conditions. OBJECTIVES To explore how mental demands and pacing influence the biomechanical response and subsequent spine loading and, to determine whether individual characteristics have a modifying role in the responses. SUMMARY OF BACKGROUND DATA Mode...

CONTEXT Increased mechanical loading can promote the preferential differentiation of bone marrow mesenchymal stem cells to osteoblastogenesis, but it is not known whether long-term bone strength-enhancing exercise in humans can reduce marrow adiposity. OBJECTIVE Our objective was to examine whether bone marrow density (MaD), as an estimate of marrow adiposity 1) differs between young female a...

Crack tip deformations and fracture parameters in functionally graded glass-filled epoxy beams are experimentally evaluated under static and dynamic loading conditions. Beams with unidirectional, monotonic elastic gradients and cracks along the gradient are examined. SEN samples with increasing or decreasing Young’s modulus ahead of the crack tip are studied in symmetric four-point bending and ...

STUDY DESIGN Cross-sectional design. OBJECTIVE To compare lumbar multifidus electromyographic activity (EMG) during predictable and unpredictable trunk loading between people with and without recurrent unilateral low back pain (LBP) during symptom remission. SUMMARY OF BACKGROUND DATA Unpredictable loading is a common injury mechanism for LBP. Paraspinal muscle responses to trunk loading di...

The reflection-mode Digital Gradient Sensing (r-DGS) method is extended to visualize and quantify dynamic deformations in solids due to stress wave propagation and for damage/disbond detection in layered materials due to impact loading. The r-DGS technique employs digital image correlation principles to quantify two orthogonal surface slopes simultaneously in specularly reflective solids. Here,...