Military platforms—such as ships, aircraft and ground vehicles—rely on advanced materials to make them lighter, stronger and more resistant to stress, heat and other harsh environmental conditions. Currently, the process for developing new materials to field in platforms frequently takes more than a decade. This lengthy process often means that developers of new military platforms are forced to rely on decades-old, mature materials because potentially more advanced materials are still being developed and tested, and are considered too large a risk to be implemented into platform designs.
DARPA’s Materials Development for Platforms (MDP) program seeks to address this problem by compressing the applied material development process by at least 75 percent: from an average of 10 years or longer to just two and a half years. The program will create a materials development methodology and toolset that is guided by platform-level “design intent.” Design intent refers to how the materials will be used in a military platform, which allows materials developers and designers to collaborate and optimize the final solution from the start based on performance needs of the platform.
MDP aims to achieve its goals through a collaborative, cross-disciplinary model that combines materials science and engineering with the platform development disciplines of engineering, design, analysis and manufacturing.
The MDP program aims to disrupt the current material development paradigm by invoking a materials development framework that artificially simulates the platform or product development sequence for a materials development effort. This framework, guided by design intent, is intended to be an all-encompassing, cross-disciplinary, collaborative methodology that reduces the time required to mature and transition new materials to new products and platforms.
Design intent is the functional role of the materials systems at conceptual design, instead of waiting until a preliminary design has been completed and for design requirements to flow down. Developing new materials based on design intent will allow designers and materials developers to collaborate and optimize solutions based on material attributes and performance needs and will allow rapid assessment, optimization, and maturation of material systems to meet platform design intent and manufacturability requirements.
In the context of MDP, “cross disciplinary” has a specific meaning that begins with, but is not necessarily limited to, integrating materials and processing, manufacturing, and true integrated computational materials engineering (ICME) principles with platform engineering, design, and analysis disciplines. Deliberate focus is placed on true ICME principles—i.e., using modeling and simulation as a tool to guide material development—rather than efforts solely to improve fidelity and accuracy of models and simulations themselves.
Further, mature verification, validation, and uncertainty quantification techniques should be used to quantify the accuracy and precision of predictive tools. It is generally accepted that inaccurate and imprecise modeling and simulation outputs can still be useful as long as levels of inaccuracy and imprecision can be quantified. MDP is experimenting with incorporation of materials informatics disciplines, which aim to apply contemporary data analysis techniques to the disparate sets of data developed during a materials and product development effort.
These data could be as varied as processing parameters, micrographic images of morphology, chemical properties, mechanical properties, and stress and thermal distributions—wholly dissimilar sets of information that are usually analyzed in a heuristic fashion by experts and connected via heuristic and knowledge-based processes. Instituting data reduction techniques as required, MDP will determine whether novel interrelationships and new insights can be extracted based purely on a data-analysis approach.
MDP also is exploring the field of metrology to identify whether there is new measurement science for representing environments or operational conditions and for extracting operationally relevant behavior of materials in these environments. This is key, because often platform or product development characterization techniques are too expensive for material developers to leverage, so they typically use smaller-scale, streamlined characterization techniques that may not represent what product developers need. Characteristics that are relevant to product developers must then be extracted or assumed from these small-scale measurements.
MDP’s new methodology will incorporate manufacturing technology capabilities and constraints, or manufacturability, as part of the development cycle. In the traditional acquisition cycle, engineering and manufacturing development begins after milestone B, at which point all the component technologies have been brought forward. Therefore, manufacturing is typically not even considered until the platform’s critical design review has been concluded. MDP aims to bring together manufacturing specialists, materials developers, and designers to integrate their activities very early in the design cycle to facilitate rapid assessment, optimization, and maturation of material systems and designs to meet platform design intent and manufacturability requirements. This allows designers and materials developers to collaborate and optimize final designs in considerably less time. It is critical that independent verification and validation of MDP subcomponents be incorporated throughout all aspects of this process.
More specifically, two levels of testing and assessment will be incorporated: thermostructural characterization at the coupon level using unique methods and instrumentation; and operationally relevant arc-jet testing for accurate extraction of material characteristics of subcomponents that incorporate relevant geometric complexity and relevant size-scale (see sidebar). MDP’s overall success relies on its execution component to rapidly assess, optimize, and mature material systems to meet platform design intent and manufacturability requirements.
MDP’s vision is that collaborative and rapid design and development iteration cycles will be much more efficient in the overall platform development. In other words, iterative design–build–test cycles will outperform vastly a sequence of design– design–design–design–build–test. MDP will demonstrate this methodology and tool capability through subcomponent testing. The initial 30-month program phase will establish necessary methodology and toolsets.
Materials for Hypersonic vehicles
Hypersonic vehicles MDP has chosen an application to develop and exercise the framework: hypersonic material systems for a boost-glide hot structure aeroshell. Boost-glide defines a specific category of trajectory and platform; aeroshell indicates that this is a single-piece exterior or outer mold line; and hot structure indicates that the outer mold line functions as thermal insulation and as a primary load-carrying structure.
This application is extremely challenging because of the extreme environment and operational conditions, which truly push boundaries of the materials and platform designed. However, the application is relevant, because current operational baselines are limited by available materials, and because there is a large quantity of low- to mid-maturity materials available.
To establish design intent, an MDP Broad Agency Announcement presented a representative boost-glide flight profile that sets the aero–thermal–chemical environment in which the vehicle will operate. An approximate vehicle description also was provided to MDP proposers to help translate the flight profile into vehicle loading conditions. Vehicle integration artifacts, including bulkheads, joints, and seals, must be developed and represented in subcomponent designs to avoid surprises when materials are scaled up from coupons to full-scale articles—a necessary outcome of this interdisciplinary framework guided by design intent.
Independent verification and validation of subcomponents will be conducted in operationally relevant environments, because final MDP materials and designs will be subjected to ground tests that simulate the conditions of representative flight conditions. The hypersonic vehicle use case will force material design communities to integrate their tools successfully to meet the MDP goal of a 30-month development timeline.
Multidisciplinary Team Receives DARPA Award to Develop Novel Magnetic Materials
Researchers at Ohio State University (OSU) have received a $6.34-million U.S. Defense Advanced Research Projects Agency award to develop novel magnetic materials by unlocking the power of skyrmions, nanoscale spin textures with the potential to advance data storage miniaturization technologies.
Skyrmions could be important for creating smaller magnetic information storage that is still stable and efficient, and skyrmion-based memories are likely to be more energy efficient than conventional magnetic memories.
Over the course of the project, the researchers will study new material platforms that can hold skyrmions. Once a novel magnetic material is developed, the team will probe the skyrmions and image the material to ensure they exist, and then will start manipulating the material to create a prototype memory-storage device.
“The ultimate in spatial resolution imaging will be essential as we work towards stabilizing these exciting new structures at room temperature,” says OSU professor David McComb.