SOW.pdf

NASGRO Development Phase 11 - Statement of Work (SOW) April 22, 2024 Summary: Provide Phase 11 professional development services to implement features in NASGRO that will enable the performance of fitness-for-service (FFS) and fatigue crack growth (FCG) analyses consistent with the approaches outlined in API 579 - 2021. The objectives of these tasks are to simplify the NASGRO inputs such that it is easier for the user to follow the API 579 approaches and use API 579 materials data.

Short title:

NASGRO Phase 11 development, tasks 8 (cont.), 13a, 13b, 14, 15 and 16 for pressure vessel and piping applications.

Background NASA’s Office of Safety and Mission Assurance (OSMA) and NASA Ames Research Center’s Pressure Systems Manager (PSM) on behalf of all NASA Centers require the ability to evaluate the fitness for service and remaining safe life of ground-based pressure vessels and pressurized systems that experience cyclic pressure, mechanical and thermal loadings during operation that causes fatigue / fracture damage and crack growth. Commercially available software that offers this capability does not adequately address NASA’s technical requirements for layered vessels, is very expensive, and requires per-user seat license procurement and annual maintenance contracts for upgrades and security patching. Therefore, NASA desires to use the NASGRO fracture mechanics analysis software since the Agency has unlimited free use rights through the Space Act Agreement (SAA) signed with Southwest Research Institute (SwRI), who is the legal copyright holder for the software. However, further development is required for its desired application to NASA’s fleet of pressure vessels and piping systems, and this phased development effort is NASA’s investment to develop and mature the software for such use by all Centers.

NASGRO was initially developed in the 1980s by Lockheed Martin Services (LMS) under contract to NASA to meet space flight program fracture control requirements, but the features required for current assessment of institutional ground-based pressure vessels and piping systems were generally not included in that development. In 2000, an SAA was signed with SwRI for the collaborative development and commercialization of NASGRO to ensure its ongoing availability and support through the establishment of a fee-based industry consortium with SwRI serving as the managing partner and principal developer. At the same time, the NASGRO copyright was reassigned and transferred from LMS to SwRI, who retains it to the present. Under the terms of the SAA, NASA retains a perpetual royalty-free license for use of NASGRO for NASA programs and projects. NASA is not a consortium member, however, and any NASA-specific development tasks must be funded by NASA. NASA JSC continues funding the development of space flight related fracture control features and improvements, while NASA’s Office of Safety and Mission Assurance (OSMA) has provided incremental funding of tasks related to ground-based pressure vessels and systems since 2014 with Phase 1 of this effort. It is anticipated that additional development phases will be undertaken in the future as funds become available.

NASA’s policy in NPR 8715.1B (chapter 7) and pressure system safety requirements in NASA STD- 8719.17C and NASA STD 8719.26 require that each NASA Center demonstrate the safety, fitness for service, and remaining safe life of potentially hazardous ground-based pressure vessels and systems.

NASGRO Phase 11 development

NASA has many such systems that are both vital to NASA’s mission and present significant potential hazards to staff. Most vessels are subjected to cyclic service loadings, and many were fabricated from undocumented, non-Code materials and processes. Standard ASME Code rule-based techniques are often inadequate for addressing the in-service conditions and features of these vessels without excessive conservatisms, and the specialized capabilities of fracture mechanics and cyclic crack growth software is needed to provide remaining safe life assessments of such legacy equipment. In addition, industry codes and standards mandated by OSHA (e.g., ASME Boiler & Pressure Vessel Code, and ASME FFS-1 / API-579 Fitness for Service) require the application of the failure assessment diagram (FAD) approach and its underlying analytical methodologies in these assessments. NASGRO did not originally address the ASME/API FAD approach because the consortium members and JSC interests were in aerospace rather than ground-based vessels, but this has been included in the completed tasks of this phased work. NASGRO requires ongoing targeted engineering and software development to fully incorporate the ASME/API stress intensify factor (SIF) models and weight function methodologies and to provide options for consistency with API-579 – 2021 outputs. An updated plan of development tasks was agreed upon with NASA in 2018 and the current task reference numbers reflect the updated plan and task 16 which new in the current effort.

This document is the Phase 11 development SOW. The subtasks listed below require fracture mechanics engineering, software coding, verification and validation testing, reporting, and project management in accordance with SwRI standards. The successful completion of this work will benefit NASA and industry through improved safety assessments with the incorporation of the desired capabilities in future commercial releases of NASGRO.

1. Objective

The bidder shall perform Phase 11 engineering and software development including graphical user interface (GUI) tasks as a follow-on to Phase 1 - 10 work to incorporate prior development and enhance NASGRO’s API-579 capabilities and compatibility as related to assessment of NASA’s institutional ground-based pressure vessels and systems. This work requires completing development tasks, documentation of progress and functionality reports, and publishing NASGRO updates for user community assessment. Execution of this work requires a single source procurement to SwRI, the sole legal copyright and SAA holder, based on the sole source justification provided separately.

2. Scope & Specifications

Perform Phase 11 NASGRO development by completing the six tasks listed below. All work shall be based on the current release of API-579, 2021 edition.

Task 8 (cont’d): Investigate Compatibility of NASGRO SIF models with API 579 solutions.

Comparisons of NASGRO SIF solutions with corresponding SIF solutions from API 579 have been an ongoing effort in Phase 9 and 10 and will continue in Task 11 with a focus on documenting the comparisons and results. This effort will also include comparisons of reference stress solutions and will document differences in results and their most likely explanations. The primary focus of this comparative effort will be the NASGRO circumferential surface crack model in a pressurized cylinder SC34 and the corresponding API 579 model KCSCCE2. Other solutions will be investigated as resources permit. The results of this task will feed into the construct of the Task 15 report. Recommendations for future development and/or comparisons will be provided.

In Phase 10, a key difference in the formulation of the reference stress was identified for these two circumferential surface crack solutions (including a difference between the API 579 2016 and 2021 editions). The API 579 2021 KCSCCE2/RCSCCE1 solution now uses a biaxial stress formulation to compute the reference stress. In this task, an option will be implemented in NASFLA and NASFAD for the user to choose the API 579 2021 reference stress solution for SC34.

Task 13a: Provide Capability to Use API 579 Fracture Toughness in NAS CCS

In Phase 10, the capability for a user to calculate a lower bound fracture toughness (KIc) using the API 579 Equations was implemented as an option on the NASGRO material screens for NASFLA and NASFAD. The goal of this task (13a) is to implement the same capability as an option in the critical crack size module (NASCCS).

Task 13b: Provide Capability to Access the NASGRO Material Database from NASCCS

NASFAD contains the capability to access the NASGRO material database. The goal of this task (13b) is to implement the same capability as an option in the critical crack size module (NASCCS)

Task 14 (cont’d): Provide Capability to Simply Use the Paris Equation in NASFLA

It is already possible to specify a Paris equation in NASFLA via the NASGRO equation by making specific choices for various parameters in the NASGRO equation. The new simpler approach designed in Task 10, will allow the user to specify API 579 Paris equations in the GUI by accessing them in tabular data formats from NASGRO material database files. This option would be present as new choices for “Data Source” and “Data Format” in the material selection process. This capability will include the Paris equations from the 2021 edition of API 579 and Section 9F.5.3.2 that refer to the ASME B&PV Code, Section VIII, Div. 3 (Table KD-430). In addition, the legacy Barsom Paris equations for base metal and welded joints as listed in API 579 in Sections 9F.5.3.5 and 9F.5.3.6 will be included.

Task 15 (cont’d): Provide a Report Documenting the Use of NASGRO for API 579 Analyses

The objective of this task is to produce a report summarizing and demonstrating the use of NASGRO to perform FFS assessments and fatigue crack growth evaluations of representative pressure vessel examples in accordance with API 579 - 2021 procedures. The report is planned to include (at a minimum):

• Comparison of NASGRO and API 579 SIF solutions

• Overview of key NASGRO SIF models for pressure vessel (PV) analyses

• Specification of material properties (strength, fracture toughness, FCG rates)

• Specification of weld residual stress distributions

• Overview of Failure Assessment Diagram (FAD) failure criteria

• NASGRO FAD options

• Using NASFAD for FFS assessment

• Using NASFLA for fatigue crack growth analyses

• Examples for different PV geometries, crack orientations, and shapes

The Phase 10 objective for Task 15 was to develop a detailed outline of this report. The full report will be completed in Phase 11.

Task 16 (new): Add Material Data for A-106 Gr B Steel to NASGRO

The objective of this new task would be to add A-106 Gr B material data to NASGRO from a 1993 EFM paper (by Liaw, Saxena, and Perrin). This paper contains an excellent set of data (yield and ultimate stress, fracture toughness, and da/dN data (at R=0.1) at two temperatures (75oF and 550oF). The raw da/dN data are not available; however, Paris equation parameters were provided. Therefore, it is planned to add this material to the NASFLA database in 1-D tabular form.

Program Management

Bi-monthly progress reports will be written to track technical progress and expenditures. The new NASGRO features developed in this effort will be documented in the NASGRO Reference Manual with excerpts submitted as attachments to the progress reports. Access to the evaluation versions (11.1 alpha and 11.1 beta) will be provided to NASA pressure vessel engineers as needed to enable them to review the new features.

3. Period of Performance

Work to begin as soon as possible which is assumed to be no later than May 31, 2024 and will extend through May 31, 2024.

4. Deliver to:

NASA ARC Pressure Systems Manager Building N-237, room 213 Moffett Field, CA 94035-0001