Proceedings of the Vertical Flight Society 76th Annual Forum最新文献

{"title":"Towards Unified Probabilistic Rotorcraft Damage Detection and Quantification via Non-parametric Time Series and Gaussian Process Models","authors":"Ahmad Amer, F. Kopsaftopoulos","doi":"10.4050/f-0076-2020-16276","DOIUrl":"https://doi.org/10.4050/f-0076-2020-16276","url":null,"abstract":"\u0000 The complex dynamics of rotorcraft structures under varying operational and environmental conditions demand the development of accurate and robust-to-uncertainties structural health monitoring (SHM) approaches. The inherent uncertainty within monitoring data makes it difficult for conventional methods to accurately and robustly detect and quantify damage without the need for a large number of data sets. In addition, due to the time-varying nature of rotorcraft operations, such conventional metrics might still fail even with abundance of data. In this paper, we propose a unified probabilistic damage detection and quantification framework for active-sensing, guided-wave SHM that focuses on monitoring rotorcraft structural \"hotspots\". The proposed framework involves three stages: The first stage incorporates statistical damage detection based on stochastic non-parametric time series (NP-TS) models of ultrasonic wave propagation signals within a hotspot sensor network configuration. The second stage involves the statistical path selection, where a NP-TS representation is used for the sole purpose of identifying damage-intersecting signal (wave propagation) paths, that is the paths that are most sensitive to damage, in order to use them in the subsequent damage quantification stage. That last stage achieves probabilistic damage quantification, where the results of the NP-TS models are used to train Bayesian Gaussian Process regression and classification models. This unified framework ensures accurate and robust damage detection and quantification in a data-efficient manner since only damage-intersecting paths are selected and used in the analysis. The performance of the proposed framework is compared to that of conventional state-of-the-art damage indices (DIs) in detecting and quantifying simulated damage in two representative coupons: a Carbon Fiber Reinforced Polymer (CFRP) coupon and a stiffened aluminum (Al) panel. It is shown that the proposed framework outperforms conventional DI-based active-sensing guided-wave SHM methods.\u0000","PeriodicalId":293921,"journal":{"name":"Proceedings of the Vertical Flight Society 76th Annual Forum","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115855065","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Advances in Property Model Methodology (PMM)","authors":"P. Micouin, Micouin Consulting, Louis Fabre, C. Gaurel, Nicolas Martignago, P. Pandolfi, Pascal Paper, T. Razafimahefa","doi":"10.4050/f-0076-2020-16360","DOIUrl":"https://doi.org/10.4050/f-0076-2020-16360","url":null,"abstract":"\u0000 This paper reports on the current state of experimentation and deployment of the PMM method within the Design Office of Airbus Helicopters (AH). It shows that it is possible to efficiently carry out a system engineering process based on modeling and simulation (MS4SE). It is based on simulation tools that are widely available and known to engineers in the practice of their disciplines. The PMM method has not yet been used at AH on a complete helicopter program. This is owed in part to the too recent emergence of PMM. However, PMM has gone through several qualification stages in the form of Proofs of Concept (POCs) and pilot projects conducted directly in relation with operational teams and engineering disciplines interested to PMM for the greatest benefit of end users. The paper presents results for each stage of the development cycle paying a particular attention on both ends of this cycle: from the development of the operational concept and the validation of the top-level specification to the final verification of a helicopter function on an integrated helicopter test laboratory.\u0000","PeriodicalId":293921,"journal":{"name":"Proceedings of the Vertical Flight Society 76th Annual Forum","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124709442","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bell 505 JRX, 250 Aircraft Delivered and Counting!","authors":"Patrick Paquin, Y. Lavallée","doi":"10.4050/f-0076-2020-16450","DOIUrl":"https://doi.org/10.4050/f-0076-2020-16450","url":null,"abstract":"\u0000 Since certifying the Bell 505 in December 2016, customers on six continents have received delivery of 250 of these light, single-engine aircraft. In three years the worldwide fleet logged more than 35,000 flight-hours, a testament to the Bell 505's customer experience - not only with the aircraft, but with delivery and service. In getting to the 250th delivery, the paper discusses the efforts taken to meet market demand, provide custom finishing, offer kit integration, and even take on additional envelope expansion. Numerous configurations and kits were made available a short time after initial certification, allowing Bell 505 customers to take full advantage of the aircraft capability in a timely manner. The challenges of meeting market demand and transitioning from low rate production to full rate production requires a team effort and this paper shows how it was done for the 505.\u0000","PeriodicalId":293921,"journal":{"name":"Proceedings of the Vertical Flight Society 76th Annual Forum","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131552275","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Low-Order Prediction of Mineral Dust Sticking Probability in Turboshaft Engines","authors":"Matthew Ellis, N. Bojdo, A. Filippone, Merren A. Jones, A. Pawley","doi":"10.4050/f-0076-2020-16338","DOIUrl":"https://doi.org/10.4050/f-0076-2020-16338","url":null,"abstract":"\u0000 Rotorcraft operations in arid environments can result in the ingestion of large quantities of dust particles into turboshaft engines, where they can melt and deposit on high pressure turbine nozzle guide vanes. This can result in reduced engine life-span and in worst case scenarios, in-flight engine failure. Predicting the extent and rate at which this damage occurs has proven difficult owing to the wide range of variables relating to the dust cloud, engine and most importantly, the properties of the particulate encountered. Whilst significant work has been carried out to model the particle deposition process for both volcanic ash and coal fly-ash, there is scarce similar work for the different types of mineral dusts rotorcraft encounter. In this contribution, we assess the suitability of two opposing numerical approaches for use in a generalised, reduced-order deposition model of individual mineral particles depositing on a vane. Both models are seen to be heavily reliant upon empirical inputs, be this the thermo-mechanical properties of the particles such as their yield strength, or currently unknown experimentally determined constants. An alternative approach is therefore proposed whereby the particle yield strength is correlated using existing relationships to the Vickers hardness of the grain, a property more amenable to empirical determination. The results obtained represent the current applicability limits of the two models based upon existing empirical data and thus highlight the need for further experimentation relating to both the thermo-mechanical properties and probabilities of adhesion for both individual mineral grains and mineral dust blends.\u0000","PeriodicalId":293921,"journal":{"name":"Proceedings of the Vertical Flight Society 76th Annual Forum","volume":"38 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132242097","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Determining TH-1H Tailboom Loads from Measured Strain Gage Data","authors":"D. Taylor, M. Gibson, Murray R. Mason","doi":"10.4050/f-0076-2020-16352","DOIUrl":"https://doi.org/10.4050/f-0076-2020-16352","url":null,"abstract":"\u0000 This work develops tailboom aerodynamic loading for a TH-1H helicopter in hover by integrating a finite element model (FEM) and in-service strain time histories in accordance with structural mechanics and aerodynamics principles. The FEM is a whole aircraft model used to establish stress spectra at critical aircraft components for fatigue and fracture analyses from main rotor and tail rotor forces. The in-service time histories are the responses from sixteen uniaxial strain gages attached to the tailboom primary longerons and the corresponding structure inside the main cabin. Five separate loading modalities are used as FEM static load cases. Published experimental drag coefficients are used to develop two aerodynamic pressure load distributions for the tailboom as well as separate left and right elevator pressure loads. The fifth case is a lateral tail rotor force. Weighting factors are determined for these five modalities so that the weighted sums of the FEM strains best-fits the measured strains at the sixteen gage locations. This fitting process is executed for each time step of each strain gage in a given hover regime, as well as for the average gage values for the duration of the regime. Weighting factors are evaluated for admissibility (i.e. non-negative values, bounded magnitudes that do not produce unrealistically high stresses). The results are compared against the measured strains. The mechanics of the tailboom structure is also evaluated with respect to strains, longeron loads, and netsection bending moments. The findings highlight that the longerons (where the strain is measured) account for approximately two-thirds of the tail boom bending moments; the external skins and stiffeners provide the balance of the moments. Two load modality combinations emerged as best-fits: tail boom aerodynamic pressure loading plus tail rotor force, and elevator pressure loading plus tail rotor force. Both show varying levels of fidelity to the measured data, which suggests that additional load modalities should be considered, and that additional instrumentation of the skins should be implemented for future strain surveys.\u0000","PeriodicalId":293921,"journal":{"name":"Proceedings of the Vertical Flight Society 76th Annual Forum","volume":"93 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122729376","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental and Numerical Investigation of Interaction Between Rotor and Wing at High Advance Ratio","authors":"Y. Tanabe, N. Kobiki, H. Sugawara, Hirotaka Hayashi, Kobayashi Wataru, Ryosuke Satou","doi":"10.4050/f-0076-2020-16364","DOIUrl":"https://doi.org/10.4050/f-0076-2020-16364","url":null,"abstract":"\u0000 In this paper, an experimental and numerical study of a rotor interacting with wing of three different aspect ratios at an advance ratio of 0.5 is described. Those three wings have the equal area and fixed at an angle of attack of 8 degrees. One wing is installed at 3 different vertical positions and three different horizontal locations to investigate the influence of the wing position on the interaction. The calibration and correction process of the measurement is described, and the results are compared to pre-test CFD simulations. Numerical simulations based on simplified rotor and wing-body models have been carried out ahead of the wind-tunnel testing. Due to the existence of rotor-test-stand and the rotorhub which are not included in the CFD simulations, the measured aerodynamic performance deviated from the CFD results remarkably. By applying angle-of-attack and drag offset corrections which remove the influence of the rotortest-stand, the wing performance is found in good agreement with the CFD results. Also, applying hub-correction which is based on measured hub-only aerodynamic force components, and the angle-of-attack correction, the corrected isolated rotor performance in high advance ratio agrees satisfactorily with the CFD data. It is found that due to the rotor/wing interaction, the overall lift-to-effective drag ratios decrease about 12% at the advance ratio of 0.5.\u0000","PeriodicalId":293921,"journal":{"name":"Proceedings of the Vertical Flight Society 76th Annual Forum","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117254421","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reducing Risk in 3D Printed Composite Tooling","authors":"Eric Dunn","doi":"10.4050/f-0076-2020-16280","DOIUrl":"https://doi.org/10.4050/f-0076-2020-16280","url":null,"abstract":"\u0000 For high end composite manufacturing in a rapid development environment, the long lead item is often the hard tooling, in particular the cure mold. A traditional metal mold takes in the neighborhood of four to nine months to design, fabricate and validate. With high temperature capable print materials, and larger and faster printers, Additive Manufacturing (AM) appears to have high potential in this area of advanced composites manufacturing. Sikorsky has used AM very successfully on a scale up to approximately 3'x3' and cure temperatures of 350°F. Though long-term durability is still to be determined; the materials, technologies, and techniques Sikorsky has employed for AM autoclave cure molds on this scale have consistently exceeded expectations. AM tools along the scale of main rotor blades could be leveraged to realize even more significant cost and schedule gains from AM autoclave tooling, and in this area, there are still more questions than answers when it comes to a dependable tooling solution. Rotorcraft development, in particular Future Vertical Lift (FVL), programs offer an opportunity to realize the significant schedule and cost benefits AM can provide for composite tooling.\u0000","PeriodicalId":293921,"journal":{"name":"Proceedings of the Vertical Flight Society 76th Annual Forum","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121417734","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Future Vertical Lift Digital Backbone, Navigating Technology and Implementation Details","authors":"H. Tiedeman, Branden Sletteland, Max G. Taylor, Collins Aerospace","doi":"10.4050/f-0076-2020-16431","DOIUrl":"https://doi.org/10.4050/f-0076-2020-16431","url":null,"abstract":"\u0000 The current US DoD has recognized that their asymmetric advantage is eroding1. Adversaries have had over 25 years to counter the US playbook and weapon systems (Ref. [1]). The US Army Future Vertical Lift (FVL) programs have identified several key tenets that their airborne weapon systems need to ensure they maintain asymmetric advantage. \u0000(1) New and upgraded mission capabilities of their airborne platforms need to get to the field faster (Ref. [2]). One of the current roadblocks to achieving this is the extensive full-system regression testing that ends up being required when there are mission system changes (Ref. [3]). \u0000(2) More competition is needed to help generate \"quicker, better, faster\" capabilities (Ref. [4]). \"Vendor lock\" inherent in current system designs hinders the speed at which technology advances (Ref. [4, 5]). \u0000(3) Improved portability of mission capability across the FVL and enduring fleet (Ref. [6, 7]). The ability to more easily reuse technology will help maintain advantage by eliminating the time needed to develop platform specific solutions (Ref. [4, 6]). \u0000The request for Modular Open System Architecture (MOSA) solutions has been a practice to try to address the items above (Ref. [8]). Most air vehicle and mission system providers are today providing MOSA solutions but the required benefits have not yet been fully realized. MOSA standards as they exist today do a very good job of identifying electronics hardware and software architectures. However, they fall short on physical aircraft integration and consistency in architecture among aircraft systems. Minimizing aircraft wiring and structural modifications, increasing speed to fielding, and portability among multiple systems types are all part of integrating highly MOSA compliant solutions. \u0000The US Army FVL programs have required a \"digital backbone\" (Ref. [7, 9, 10]) to address these integration issues and ensure that they can maintain asymmetric advantage. Unique requirements affecting the digital backbone include:\u0000- Power and power distribution (Ref. [9]) \u0000- Thermal management (Ref. [9, 11]) \u0000- Packaging and installation (Ref. [9]) \u0000- Air Vehicle data distribution (Ref. [9]) \u0000- Mission System data distribution (Ref. [9]) \u0000- Isolation of air vehicle and mission system (Ref. [9]) \u0000This paper will provide an introduction to the envisioned digital backbone for US Army, Future Vertical Lift aircraft. The paper will also offer discussion of digital backbone impacts on aircraft and avionics size, weight, power and cost, as well as technology considerations to address interoperability, safety, security, qualification, and accommodations for new, as well as, legacy avionics technology. \u0000","PeriodicalId":293921,"journal":{"name":"Proceedings of the Vertical Flight Society 76th Annual Forum","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116615562","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Low AOB Component Loads Derivation to Implement MH-60R HUMS","authors":"S. Moon, D. Liebschutz, Navair","doi":"10.4050/f-0076-2020-16349","DOIUrl":"https://doi.org/10.4050/f-0076-2020-16349","url":null,"abstract":"\u0000 Presently the fatigue lives of MH-60R dynamic components and airframe are based on a usage spectrum developed using pilot surveys. In order to better define the usage spectrum and to extend component and airframe fatigue life, the Health & Usage Spectrum (HUMS) System was installed on the U.S. Navy MH- 60R Rotorcraft. So far 207 aircraft are equipped with the HUMS systems and 121,334 flight hours of good data have been recorded. The regime recognition programs recognize 315 maneuvers, but are consolidated to 94 maneuvers of MH-60R usage spectrum, for which the component measured loads are available. To better define usage spectrum in detail and compute realistic component fatigue life, an additional maneuver of low Angle Of Bank (AOB) from 10 to 25 degrees was added, but the measured component loads were not available at this AOB to implement HUMS. Thus, measured flight loads data of level flight and AOB turns at 30, 45, and 60 degrees were utilized to derive component loads at 20 degrees by spline cubic interpolation technique. The cubic interpolation technique was applied to measured minimum, average, and maximum loads of variation at 10, 30, 45, and 60 degrees to interpolate load at 20 degree. This technique was applied to interpolate loads for pitch control rod, swash-plate, drag damper, shaft bending moments, blade cuff stresses, and flap deflections. The spline interpolation loads correlated with measured available loads of pitch control rod and blade stresses. The probabilistic fleet usage spectrum of various severities was developed using the HUMS recorded data of 121, 334 hours from 179 rotorcraft with and without low AOB usage. It is evident that fatigue life with 20 AOB split is significantly higher for all dynamic components. Thus, to implement HUMS successfully, it is necessary to compute loads that are not available in the original component fatigue life calculations. Further prorates of gross weigh (GW), velocity and altitude based on the HUMS fleet usage should be implemented to extend component fatigue lives. \u0000","PeriodicalId":293921,"journal":{"name":"Proceedings of the Vertical Flight Society 76th Annual Forum","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115096622","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Motion Primitive Perspective on Rotorcraft Regime Recognition","authors":"Umberto Saetti, Jonathan D. Rogers","doi":"10.4050/f-0076-2020-16266","DOIUrl":"https://doi.org/10.4050/f-0076-2020-16266","url":null,"abstract":"\u0000 An alternative approach to regime recognition that is based on the notion of motion primitives is developed. The algorithm developed is non-causal and leverages the ideas of maneuvers and trims as defined in a motion primitive context. The algorithm functions in three major steps. Given a state and control input time history obtained from flight data, the first step consists of classifying the state and control time history into trim and maneuver segments. The second step leverages the information in the trim state and control vectors to classify each trim segment into a particular trim condition based on conditional (if-else-if) logic. The third step entails the classification of each maneuver segment (flown between two trim segments) as a particular maneuver condition. Importantly, maneuver classification leverages dynamic time warping in order to compensate for rate and time duration variations. Accuracy of the proposed algorithm is evaluated using SH-60B simulated flight data. Operation of the algorithm is also demonstrated using real-world piloted flight test data from a generic utility helicopter.\u0000","PeriodicalId":293921,"journal":{"name":"Proceedings of the Vertical Flight Society 76th Annual Forum","volume":"333 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115771151","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}