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Technical Paper

The irrotational intensity: an efficient tool to understand the vibration energy propagation in complex structures using an FE Model.

2024-06-12
2024-01-2942
Although structural intensity was introduced in the 80's, this concept never found practical applications, neither for numerical nor experimental approaches. Quickly, it has been pointed out that only the irrotational component of the intensity offers an easy interpretation of the dynamic behavior of structures by visualizing the vibration energy flow. This is especially valuable at mid and high frequency where the structure response understanding can be challenging. A new methodolodgy is proposed in order to extract this irrotational intensity field from the Finite Element Model of assembled structures such as Bodies In White. This methodology is hybrid in the sense that it employs two distinct solvers: a dynamic solver to compute the structural dynamic response and a thermal solver to address a diffusion equation analogous to the thermal conduction built from the previous dynamic response.
Technical Paper

A Methodology for Accelerated Thermo-Mechanical Fatigue Life Evaluation of Advanced Composites

2024-06-01
2024-26-0421
Thermo-mechanical fatigue and natural aging due to environmental conditions are difficult to simulate in an actual test with the advanced fiber-reinforced composites, where their fatigue and aging behavior is little understood. Predictive modeling of these processes is challenging. Thermal cyclic tests take a prohibitively long time, although the strain rate effect can be scaled well for accelerating the mechanical stress cycles. Glass fabric composites have important applications in aircraft and spacecraft structures including microwave transparent structures, impact-resistant parts of wing, fuselage deck and many other load bearing structures. Often additional additively manufactured features and coating on glass fabric composites are employed for thermal and anti-corrosion insulations. In this paper we employ a thermo-mechanical fatigue model based accelerated fatigue test and life prediction under hot to cold cycles.
Standard

Sheet and Strip Surface Finish Nomenclature

2024-05-16
CURRENT
AS4194B
This SAE Aerospace Standard (AS) defines the nomenclature for surface finishes commonly used for sheet and strip in aerospace material specifications. It is applicable to steel and to iron, nickel, cobalt, and titanium base alloys.
Technical Paper

Surface Properties of Shot-Peened and Plasma Sprayed Powder-Coated Alpha-Beta Titanium Alloy Implants

2024-05-15
2024-01-5060
The paramount importance of titanium alloy in implant materials stems from its exceptional qualities, yet the optimization of bone integration and mitigation of wear and corrosion necessitate advanced technologies. Consequently, there has been a surge in research efforts focusing on surface modification of biomaterials to meet these challenges. This project is dedicated to enhancing the surface of titanium alloys by employing shot peening and powder coatings of titanium oxide and zinc oxide. Comparative analyses were meticulously conducted on the mechanical and wear properties of both treated and untreated specimens, ensuring uniformity in pressure, distance, and time parameters across all experiments. The outcomes underscore the efficacy of both methods in modifying the surface of the titanium alloy, leading to substantial alterations in surface properties.
Standard

Reaffirm E 2024 - spring

2024-05-13
WIP
REFIRM-E-S2024
The following document were been proposed by the sponsor or by committee E for Reaffirmation at the Spring meeting 2024.
Standard

Nuts, Self-Locking, UNS N07001 730 °C, 1100 MPa, and 1210 MPa Procurement Specification for, Metric

2024-05-09
CURRENT
MA1943C
This procurement specification covers aircraft quality self-locking nuts for wrenching (hex, spline) and anchor (plate, gang channel, shank) types of nuts made from a corrosion and heat-resistant nickel-base alloy of the type identified under the Unified Numbering System as UNS N07001. Tension height nuts having overall length of threaded portion not less than 1.2 times the nominal thread diameter have 1210 MPa minimum tensile strength at room temperature. Shear height nuts having shorter threaded portion have 1100 MPa minimum tensile strength at room temperature. Maximum test temperature of parts is 730 °C.
Magazine

Aerospace & Defense Technology: May 2024

2024-05-09
Explaining MOSA from the Team that Led the Army Aviation Mission Computing Environment Task Order What's the Best DC Motor for Your Commercial Aerospace Application? Aerospace Production: Overcoming Challenges in Composite Machining Understanding the Limits of Artificial Intelligence for Predictive Maintenance Pushing the Limits: Engineering Advanced RF Interconnects to Meet the Challenges of Hypersonic Missile Development Expanding Possibilities for Superconducting Qubits With Niobium Researchers Help Robots Navigate Efficiently in Uncertain Environments A new algorithm reduces travel time by identifying shortcuts a robot could take on the way to its destination.
Journal Article

Experimental Analysis of Heat Transfer Post Quenching of Medium Carbon Steel

2024-05-08
Abstract Transient temperature analysis is involved in the thermal simulation of the heat treatment process, in which the hot metal temperature changes with respect to time from an initial state to the final state. The critical part of the simulation is to determine the heat transfer coefficient (HTC) between the hot part and the quenching medium or quenchant. In liquid quenching, the heat transfer between the hot metal part and water becomes complicated and it is difficult to determine HTC. In the current experimentation a medium carbon steel EN 9 rod with a diameter of 50 mm and length 100 mm was quenched in water and ethylene glycol mixture with different concentrations. A part model was created; meshed and actual boundary conditions were applied to conduct computational fluid dynamics (CFD) analysis. In order to validate CFD analysis the experimental trials were conducted.
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