Abstract
Marine composite materials typically exhibit significant rate dependent response characteristics when subjected to extreme dynamic loading conditions. In this work, a strain-rate dependent continuum damage model is incorporated with multicontinuum technology (MCT) to predict damage and failure progression for composite material structures. MCT treats the constituents of a woven fabric composite as separate but linked continua, thereby allowing a designer to extract constituent stress/strain information in a structural analysis. The MCT algorithm and material damage model are numerically implemented with the explicit finite element code LS-DYNA3D via a user-defined material model (umat). The effects of the strain-rate hardening model are demonstrated through both simple single element analyses for woven fabric composites and also structural level impact simulations of a composite panel subjected to various impact conditions. Progressive damage at the constituent level is monitored throughout the loading. The results qualitatively illustrate the value of rate dependent material models for marine composite materials under extreme dynamic loading conditions.
Highlights
The use of advanced composite materials for marine structures will achieve substantial space and weight savings, but will reduce the electromagnetic signature and life cycle costs for these structures
Marine composite materials typically exhibit significant rate dependent response characteristics when subjected to extreme dynamic loading conditions [1,10, 12]
In a deviation from conventional multicontinuum technology (MCT) technology where only two states are considered for each constituent of the composite, the rate dependent MCT described uses a continuum damage mechanics approach to continuously degrade the matrix constituent properties. This MCT rate dependent material damage model for the matrix constituent utilizes a damage evolution motivated by the kinetic theory of fracture [15]
Summary
The use of advanced composite materials for marine structures will achieve substantial space and weight savings, but will reduce the electromagnetic signature and life cycle costs for these structures. Marine composite materials typically exhibit significant rate dependent response characteristics when subjected to extreme dynamic loading conditions [1,10, 12] Damage in these composites generally initiates in the polymer matrix and significantly affects the macroscopic response long before catastrophic failure. The key time saving principle to MCT is the fact that all micromechanical models are run prior to the structural analysis and are valid for any structure composed of the material of interest For this reason, the MCT-based progressive failure analysis tool is computationally efficient for dynamic failure predictions of large scale composite ship structures. While MCT does an excellent job of predicting ultimate strengths, predicted stressstrain responses show an increased deviation from the experimental data after matrix failure begins to occur This deviation is mainly attributed to the binary degradation scheme incorporated with the conventional MCT analysis tool. In a conventional MCT analysis, when failure in a constituent occurs, material properties for that constituent are subsequently zeroed, rather than being degraded in a continuous manner
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
