Mechanics of Time-Dependent Materials and Processes in Conventional and Multifunctional Materials

Fatigue Cycling of Shape Memory Polymer Resin Part 2

Shape memory response— influence of deformation rate A previous study [7] revealed that Veriflex-E exhibited strain rate sensitivity in axial tension to failure at both room and elevated temperatures. To explore the strain rate sensitivity of the shape memory response of the Veriflex-E, specimens were subjected to shape memory cycles with deformation rates of 0.5, […]

Higher Rate Testing of Long Fiber Filled Polypropylene Part 1

ABSTRACT The properties of long fiber-reinforced thermoplastics at high rates are needed to model the impact behavior of materials and structures. Testing at high rates introduces several issues, namely, bulk material property measurement, equipment capacity due to the higher failure loads, proper load introduction into the material before failure, achieving dynamic equilibrium within the timeframe […]

Higher Rate Testing of Long Fiber Filled Polypropylene Part 2

Maximum Practical Test Speeds The natural resonant frequency of the test system, approximately 7.5 to 9 kHz, was dependent on the fixture weight and load train length. Increasing the specimen size increased both the fixture weight and load train length and decreased the natural resonant frequency. . As the test speed increased, the test duration […]

Characterization of Elastomeric Composite Materials for Blast Mitigation

ABSTRACT In this work, we seek to develop elastomeric composite materials capable of shock mitigation through material design by small-scale heterogeneity. The host elastomeric material is a polyurea system that is a lightly cross-linked two-phase polymer, which consists of the diamine component Versalink P-1000 as the soft segment and the diisocyanate component Isonate 143L as […]

Experimental arrangement for measuring the high-strain-rate response of polymers under pressures

ABSTRACT This study aims to investigate the high-strain-rate shear response of viscoelastic elastomeric coatings at large strains and under elevated levels of hydrostatic pressure. Results of this study shed light on the combined effects of deformation rate and pressure which might promote a transition from viscoelastic to glassy behavior. This work utilizes a Split Hopkinson […]

Simulation of impact tests on polycarbonate at different strain rates and temperatures

ABSTRACT The use of lighter and impact resistant materials, such as polymers, in vehicular systems is an important motivation for the automotive industry as these materials would make vehicles more fuel-efficient without compromising safety standards. In general, polymers exhibit a rich variety of material behavior originating from their particular microstructural (long molecular chains) behavior that […]

Experimental Investigation of Dynamic Mechanical Properties of Polyurea-Fly Ash Composites

ABSTRACT Polyurea has been the material of choice in many applications due to its thermomechanical properties. These applications span a wide spectrum from abrasion-resistant coating to reinforcement against blast damage in structures, ships, and vehicles. The improved observed performance is linked to its microstructure, a lightly cross-linked (elastomeric) block copolymer. The constitutive modeling of such […]

Damage & Fracture of High-Explosive Mock Subject to Cyclic Loading

Abstract We use four-point bend specimen with a single shallow edge notch to study the fracture process in Mock 900-21, a PBX 9501 high explosive simulant mock. Subject to monotonic loading we determine quantitatively the threshold load for macroscopic crack initiation from the notch tip. The four-point bend specimen is then subject to cyclic loading […]

An Evaluation Of A Modified Iosipescu Specimen For Measurement Of Elastic-Plastic- Creep Properties Of Solder Materials

ABSTRACT There are various specimen configurations available in the literature for characterizing the mechanical behavior of solder interconnect materials. An ideal test specimen should use a simple geometry which produces a reasonably uniform material response throughout the gage zone and minimizes the complexity of data reduction to extract material model constants. In the thermo-mechanical micro […]

Temperature Effect on Poisson’s Ratio of Woven Composites

ABSTRACT Monotonic tensile tests were conducted following ASTM Standards D3039 (Standard Test Method for Tensile Properties of Polymer Matrix Composite Materials) and D3518 (Standard Test Method for In-Plane Shear Response of Polymer Matrix Composite Materials by Tensile Test of a +45° Laminate), on non-hybrid plain weave composite materials. Strips (6.35mmx25mmx250mm) of non-hybrid IM-7 Graphite/SC-79 epoxy […]

← Previous Entries

Next Entries →