-
E-9/M-9
Cure Management & Process Control for Composites: In and Out of Autoclave
This course is designed as an overview of the fundamentals of composite processing from a Material State Management (MSM™) perspective and how this can be used to reduce costs while improving quality and performance. Data from two new instruments will be demonstrated including sensors within the laminate without the need for a thermocouple lead penetrating the vacuum bag and near measurement of the viscoelastic state of the prepreg for acceptance and shelf-life determination. The change in viscoelastic state as it is cured will also be demonstrated and a new approach to shelf-life management will be discussed. This course has been designed to provide a fundamental understanding of the properties critical to procurement, storage, and cure of composites with the goal of teaching how and why procurement specifications, storage requirements and cure cycles were developed in the past and to demonstrate new tools that can lower cost while improving quality of the product.
-
ER-1
Aerospace Repair Analysis and Substantiation
This course is designed for degree-qualified aerospace and mechanical engineers or persons having practical experience in strength of materials calculations who are responsible for the design analysis and substantiation of repairs to secondary structures. The course is an entry level course and provides classroom lecture on composite materials, processes, and manufacturing with a focus on repair techniques and repair analysis. The hands-on shop work involves manufacturing test panels, damaging the panels, performing repairs, and mechanically testing coupons from both the original and repaired panels. The mechanical characteristics of the original and repaired panels are validated with analysis using an Excel spreadsheet, which has become one of the most recognized analysis training tools in the industry. Many students come from aircraft operators involved with commercial, business, general aviation, and military aviation, but the course is also applicable for engineers involved in original design who need to consider the design for maintainability and supportability of composite structures. The ER-1 course is a mandatory prerequisite for the ER-2 Advanced Aerospace Repair Analysis and Substantiation course, where ER-2 provides advanced composite repair analysis techniques that are applicable to primary structures.
-
ER-2
Advanced Aerospace Repair Analysis and Substantiation
ER-2 should not be considered a mere expansion of the concept already presented in ER-1. ER-2, is in fact, significantly much more. It is the direct result of over 10 years of specific R&D and thousands of hours of effort to develop an advanced repair analysis methodology that is applicable to the modern application of heavily loaded composite primary structure. When ER-1 was developed, composites were found primarily on surface panels, cowlings, landing gear door, and fairing panels - all secondary structure that did not necessarily require the most rigorous analysis. However, in modern aviation applications, composite materials are found on wings, stabilizers, flight controls and pressurized fuselages. These Damage Tolerant primary structures demand a more advanced analysis method than ER-1, of which is the central focus of ER-2. This is an advanced level course designed for degree-qualified aerospace and mechanical engineers who are responsible for the design analysis and substantiation of repairs to both primary and secondary composite structures. All students are required to have completed the ER-1 Aerospace Repair Analysis and Substantiation course to be prepared to explore a more in-depth analysis of repairs to primary structures. Although the focus is still on stiffness, strength, and composite joints, the analysis presented addresses the full in-plane and bending stiffness of composite laminates as well as a detailed representation of the most common industry used composite failure criteria. The most unique topic is the extremely in-depth analysis that is presented for evaluating the stress concentrations caused by both unrepaired damage (Allowable Damage Limits - ADLs) as well as those caused by application of different repair configurations (stiffness induced stress concentrations). This evaluation allows the determination of both the Design Limit Load (DLL) for ADLs and the Design Ultimate Load (DUL) for Damage Tolerance. This analysis meets the requirements for FAA and EASA Bonded Repair Size Limits (BRSL) and existing DoD composite repair guidelines. The ER-2 joint analysis offers solutions that are beyond any university course or professional training by presenting advanced calculations for determining the adhesive shear stress and strain across the full length of the bonded joint as well as multi-row mechanically fastened joints. Then, expanding upon the shop exercises and coupon testing in ER-1, the ER-2 workshop projects creates full circular repairs in the class panels and mechanically tests the completed repair in its entirety, without cutting the repair into test coupons. An example repair is then evaluated with FEA and mechanically tested with Digital Image Correlation (DIC).
-
ER-3/ES-4
FEA, DIC, and Advanced Stress Methods for Composite Structures and Repairs
Given the depth of information, all the advanced topics that were originally intended for ER-2 and ES-3 cannot be fully presented and explained in five days. The advanced topics primarily focus on Finite Element Analysis (FEA) and Digital Image Correlation (DIC). However, since these methods are applicable to both original structure design as well as repairs, their application was merged into a combined ER-3/ES-4 that sits at the top of the engineering training pyramid. This course has been developed to keep engineers up to date on the latest analysis and testing methods for composite structures and repairs using FEA and DIC. However, the need for analytical methods cannot be overlooked. This course also presents real-world applications of some of the most advanced stress methods that can be found in specialized composite analysis books throughout the industry that are applicable to both structural and repair analysis. FEA is widely recognized in structural analysis, so it is necessary for engineers to understand enough of the theory behind the Finite Element Method and the practical applications of FEA software to comprehend the requirements for its specific inputs and outputs - but also understand the limitations inherent to FEA. There are many unique aspects to composite FEA models that may be foreign to engineers that are familiar with FEA using metals. This course begins with identifying the proper sources for composite material properties, entering these properties into FEA, modeling a laminate in FEA, creating a laminate property, meshing the structure, applying constraints, applying loads, analyzing the model, and interpreting the results. Most engineers are familiar with stress distributions revealed with FEA, but for composites, an evaluation of the strain field, ply-by-ply failure criteria, and strain energy density is critical. Equally interesting in this course is use of Digital Image Correlation (DIC) in structural testing to validate the FEA results. DIC uses digital camera imagery taken at timed increments to digitize a speckle pattern applied to the surface of the laminate. The DIC software tracks the movement of the digitized speckles and equates it to the deformation of the structure. The analytical methods calculate the load distribution throughout the structure, that is commonly only considered to be available from FEA.
-
ES-1
Composite Essentials for Engineers and Managers
ES-1 has been developed to provide engineers and technical managers with a broad, but comprehensive understanding of composite materials and manufacturing techniques used in component development, design, and in-service operation. The course covers the major considerations for the application of composite materials with an emphasis on cost, weight, and structural requirements, material usage, manufacturing techniques, vacuum bagging, and cure cycles. The ES-1 course also covers the fundamentals of composite analysis, bonded joints, and bolted joints. The course incorporates the classroom lecture into the hands-on fabrication of fiberglass and carbon fiber prepreg solid laminate and honeycomb core panels. These panels are both bonded and bolted together and then mechanically tested to evaluate their performance and failure with the classroom analysis. ES-1 is a recommended prerequisite for all the Engineering Structures (ES) courses to ensure that the students have a sufficient understanding of composite materials and processes before they begin the learning process on more in-depth composite analysis techniques. Only engineers with extensive composite materials and process experience from OJT, or other formal training, such as Abaris' Aerospace Repair Analysis and Substantiation (ER-1) or Advanced Composite Structures: Fabrication & Damage Repair - Phase 1 (M-1/R-1) course should consider omitting this course as a prerequisite.
-
ES-2
Composite Laminate Analysis
ES-2 provides the backbone for designing and analyzing composites with a thorough understand of classical laminate plate theory and failure criteria. The ES-2 course is perfect for engineers who did not take composite courses during their university education, or who recognize that their university courses were too theoretical and did not provide enough practical understanding. ES-2 goes well beyond university level composite courses by using real-world mechanical property data for modern composite materials that are currently available and evaluating these materials on existing composite configurations. The course is 80% analysis and 20% hands-on. The shop work involves manufacturing unidirectional and woven fabric panels at the lamina and laminate level as well as mechanically loading test coupons to failure. The course performs the analysis with a highly evolved Excel spreadsheet. Additionally, it introduces the students to composite analysis using FEA. ES-2 is a prerequisite for ES-3/ES-4 unless the students have an extensive background with laminate analysis through their past work experience or university education. ES-2 is also recommended as an intermediate prerequisite between ER-1 and ER-2 for engineers performing repairs and modification who have access to load data.
-
ES-3
Design of Composite Structures
ES-3 has been developed specifically for engineers, to provide a thorough understanding of the configuration of composite details and components to meet the design requirements for structural applications. The course discusses the requirements for designing both assembled and co-cured/co-bonded structure using solid laminates, sandwich panels, stiffened structure, panel edge bands, ply drop-offs, and panel field areas. The course also addresses the requirements for assembling composite structures using both bonded and mechanically fastened joints and utilizes extremely robust bonded and bolted joint analysis techniques. Analysis is performed to evaluate panel buckling and vibration. Additionally, ES-3 provides an understanding of environmental knockdowns, BVID, allowable damage limits (ADLs), and repair-induced stress concentrations to determine design values to meet static and Damage Tolerance requirements for both primary and secondary structure. This course performs analysis with both traditional hand calculations, using MS Excel and MathCAD, and FEA, using Femap/NASTRAN.
-
ES-4
Advanced Stress Analysis Methods for Composites
This course is now merged into ER-3/ES-4. Please refer to the ER-3/ES-4 course desciption above for details.