Rapid Qualification of Fracture Mechanics and NDE Modeling

ABSTRACT:In this proposed project, a novel framework will be further developed and demonstrated to link physics-based simulations of non-destructive evaluation (NDE) methods with probabilistic fracture mechanics (PFM) analysis to support rapid qualification of advanced materials processes such as additive manufacturing (AM). In particular, the X-ray and CT simulation software XRSIM and SimCT will be linked with the PFM software DARWIN and the general-purpose probabilistic analysis software NESSUS to create a virtual reliability environment (VRE). XRSIM/SimCT will be used to determine full-field, location-specific POD curves for significant manufacturing defects that DARWIN will incorporate in predictions of fracture risk for the component in service.A prototype framework was successfully developed and demonstrated in a Phase I project. In the proposed Phase II project, the computer programs XRSIM/SimCT and DARWIN/NESSUS and their interfaces will be enhanced to substantially improve automation and efficiency of the computations, in support of improved efficiency for physical inspection plans and improved reliability for the component. Model credibility will be established through revision and execution of the verification and validation plan developed in Phase I. The integrated VRE, which will have broad applicability beyond AM, will be licensed commercially.BENEFIT:AM processes promise a long list of benefits to both legacy systems (low cost low volume parts) and new program development (lower cost prototypes early in the design cycle), but without a way to qualify parts in a highly variable piece to piece manufacturing process there is no way to trust the product.The VRE proposed here will provide a major step forward in establishing quality and hence usability in AM parts. However, the VRE isnt just tied to AM processes, but can accept process input from any other manufacturing method (either model or empirically generated).This provides a much broader list of potential applications and benefits. Specific cost savings to additive manufacturing users will come from a reduction in the number of rejected parts.When a virtual inspection is performed, lots of virtual parts can be scrapped at first.As the process is adjusted the number of virtual part rejections reaches an acceptable level.If the model has been properly calibrated and verified/validated, this will lead to fewer scrapped parts.The cost reduction is directly proportional to the reduction in rejected parts.There is also a significant design cycle time savings to be had in identifying the best process parameters needed for an optimized design, allowing for a faster response time to engineering changes and requirements. The ability to inexpensively get POD information, as provided from this projects VRE, is a huge cost savings for industry and the ability to target or zone inspections based on accurate POD and DT probabilities is a risk reducer as well.Just being able to examine an existing inspection for adequacy has huge advantages. The broader manufacturing perspective, massive investments are currently being made across the board in ICME methods for improved simulation of materials development and manufacturing processes. These simulation systems will all eventually need to carry through to address component reliability if they truly support the cradle-to-grave design, manufacturing, and life management system. Any defect-sensitive and safety-critical application will need to address NDE and POD considerations as well as fracture risk. Lastly, the proposed project will result in significant enhancements to commercially mature software and the creation of an integrated VRE that will also be licensed commercially.