Damage Behavior of Sintered Fiber Felts

Lippitz, Nicolas; Rösler, Joachim

doi:10.3390/met5020591

Cited by 6 publications

(19 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The samples were marked with copper strips to be able to analyze the same volume of the sample each time. This way of analyzing the damage behavior has been successfully performed for sintered fiber felts by Lippitz et al [16]. Here, it has been performed for material as received and for material with a thickness reduction ∆t/t 0 of 20% and 50%.…”

Section: Materials Characterizationmentioning

confidence: 99%

Modification of Porous Aluminum by Cold Rolling for Low-Noise Trailing Edge Applications

Tychsen

Lippitz

Rösler

2018

Metals

Self Cite

View full text Add to dashboard Cite

Noise reduction of aircrafts during take-off and landing has become an important part of research in aviation. The circulation of air around the airframe is a major source of noise during landing. This includes noise generated at the trailing edge. Open porous materials, such as porous aluminum, are investigated for the reduction of this noise. In this study, cold rolling is used to enhance the structure of porous aluminum in matters of aeroacoustics and mechanical properties. An important parameter characterizing the acoustic behavior is flow resistivity which is measured using the alternating airflow method. The flow resistivity is highly dependent upon the pore structure which is analyzed using three-dimensional computer tomography (CT). Additionally, CT combined with discontinuous tensile testing is used to study the influence of cold rolling on the damage behavior of porous aluminum. Besides the damage behavior, mechanical parameters have been determined to identify reasonable degrees of deformation. A cold rolling technique to produce material with a gradient in porosity is described and experimental porous trailing edges for measurements in an acoustic wind tunnel are shown. The findings of this study show that cold rolling is a promising way to customize porous aluminum for low-noise trailing edge applications.

show abstract

Section: Materials Characterizationmentioning

confidence: 99%

Modification of Porous Aluminum by Cold Rolling for Low-Noise Trailing Edge Applications

Tychsen

Lippitz

Rösler

2018

Metals

Self Cite

View full text Add to dashboard Cite

show abstract

“…The effect of rolling on the mechanical properties was also investigated by evaluating continuous tensile tests. A detailed analysis of the damage behavior, as described by Lipptiz et al [20] for as-received material using interrupted tensile tests, or by microstructure analysis and fracture surface analysis, did not take place in Tychsen et al [22]. The relevant findings of Lippitz et al [20] and Tychsen et al [22] are described in the following.…”

Section: Introductionmentioning

confidence: 93%

“…Among others, a porous aluminum and SFFs, which consist of a support grid and a functional layer, are promising from an aeroacoustic point of view [18]. Lippitz et al investigated the fouling behavior [19] and damage behavior [20] of the asreceived SFFs SFF3 and SFF100. In the course of project CRC880, a rolling process with a time-varying roll gap was introduced to set the transition in flow resistance favored by aeroacoustics.…”

Section: Introductionmentioning

confidence: 99%

Damage behavior of cold-rolled sintered fiber felts

Tychsen,

Lück,

Rösler

2024

Mater. Res. Express

View full text Add to dashboard Cite

Porous Materials, such as sintered fiber felts (SFFs), can contribute tothe reduction of aircraft noise by acting as a low-noise trailing edge (TE). A rollingprocess with a time-varying rolling gap was sucessfully used to tailor the aeroacousticproperties of SFFs. To ensure the suitability of rolled porous materials for application,the mechanical properties after rolling must be investigated. The objective of thisstudy was to clarify the effect of the rolling process on the damage evolution duringtensile loading. A SFF consisting of a functional layer and a support grid madeof alloy 1.4404 was used for rolling. Interrupted tensile tests in combination withcomputed tomography (CT) were used to investigate the damage evolution of asreceivedmaterial, uniformly rolled material and material rolled with a gradient inthickness reduction. Metallographic examination and fracture surface analysis usingscanning electron microscopy (SEM) complemented the CT analysis. Uniformly rolledmaterial with a low degree of deformation (-0.74 ≤ φ < 0) failed identically to theas-received material. The functional layer failed first, starting from the center. Thesupport grid subsequently failed due to the incremental failure of individual wires. Thematerial rolled with a gradient in thickness reduction failed accordingly. A significantchange in damage evolution occured for material rolled at high degrees of deformationφ≤-1.53, where the support grid fails first and the functional layer second. The rollingprocess using a time-varying rolling gap does not result in a detrimental mechanicalbehavior under tensile load. The results improve the general understanding of theeffects of rolling processes on the properties of porous materials and allow the damagebehavior to be taken into account with regard to its application as a TE.

show abstract

“…In this article, computed tomography and flow resistance measurements are considered and described in detail. The aforementioned methods for the characterization of the materials of the CRC 880 have been described before in literature, [18][19][20][21][22] but will be briefly explained here to facilitate discussion of their difficulties and shortcomings.…”

Section: Porous Materials Characterizationmentioning

confidence: 99%

Experimental investigation of porous materials for trailing-edge noise reduction

Rossignol

Suryadi

Herr

et al. 2020

International Journal of Aeroacoustics

View full text Add to dashboard Cite

The introduction of quiet short take-off and landing for civil aircraft operations in close proximity to the population poses important technological challenges. One critical aspect is the realization of extreme lift augmentation at low acoustic emissions. The aircraft concept selected to achieve this goal is a high-lift system equipped with an active flow-control non-slotted flap and a droop nose. For this specific configuration, trailing edge noise becomes a dominant noise source. Porous materials as a passive means for trailing-edge noise reduction are selected and characterized. Results of extensive experimental investigations in the acoustic wind tunnel Braunschweig are presented and discussed to point out the potential and limitations of the selected porous devices. Practical issues related to material manufacturing and integration into the wind tunnel model are addressed. The noise reduction potential of passive porous trailing-edge devices is found to strongly depend on both these aspects. Issues related to the characterization of the porous materials properties are described. Although porous materials are found to be successful at reducing trailing-edge noise emissions, the results indicate that there is still a need for more generic investigations to further clarify the parametric dependencies between noise reduction and material properties.

show abstract

Damage Behavior of Sintered Fiber Felts

Cited by 6 publications

References 18 publications

Modification of Porous Aluminum by Cold Rolling for Low-Noise Trailing Edge Applications

Modification of Porous Aluminum by Cold Rolling for Low-Noise Trailing Edge Applications

Damage behavior of cold-rolled sintered fiber felts

Experimental investigation of porous materials for trailing-edge noise reduction

Contact Info

Product

Resources

About