Dynamic Qualification of a New CMC Fastener

Ortelt, Markus; Ruehle, F.; Hald, Hermann; Weihs, Hendrik

doi:10.1002/3527605622.ch115

Cited by 8 publications

(7 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…7) has been screened by static and dynamic tests at ambient and elevated temperatures (100000 cycles at 1600 °C), as well as undergoing shaker tests using a sine sweep test signal equivalent to the random vibration environment during launch. The tests have confirmed the functionality of the fastener for TPS in RLVs [9].…”

Section: Ceramic Screw Rivetsupporting

confidence: 54%

Joining Techniques for Fibre Ceramic Structures

Kochendörfer

Lützenburger

Weihs

2004

Advanced Composites Letters

Self Cite

View full text Add to dashboard Cite

This paper shows three different joining methods for fibre ceramic materials. The so called in-situ joining method is an integral part of the manufacturing process for CMC structures via the liquid silicon infiltration (LSI) process. Stiffening elements, local patches within attachment areas, inserts etc. are permanently joined to shell structures, thus enabling highly integrated components to be realised with low manufacturing costs. Mechanical joining methods are required for the attachment of CMC thermal protection systems and the assembly of large structures which can not be manufactured as one part due to the limited size of manufacturing devices (e.g. autoclave, furnaces). For these cases, two different principles are available. The first method takes advantage of interlocking effects of hardened castable ceramics for permanent joints and the so called ceramic rivet, which has similar properties to metallic rivets, however using only elastic and frictional properties of the CMC basic material. The last joining method presented within this paper deals with the attachment of hot structures to a cold substructure. To solve the problems associated with thermal mismatch, elastic or kinematic attachment systems, well adapted to the thermal expansion behaviour are suitable candidates.

show abstract

Section: Ceramic Screw Rivetsupporting

confidence: 54%

Joining Techniques for Fibre Ceramic Structures

Kochendörfer

Lützenburger

Weihs

2004

Advanced Composites Letters

Self Cite

View full text Add to dashboard Cite

show abstract

“…In the center of a 7-mm-thick thermal protection panel, a porous C/C 5-mm-thick sample of the dimensions 61 × 61 mm 2 is inserted. This porous sample is to be run through by the coolant and is flanged into the surrounding TPS panel by a pressure reservoir and riveted ceramic fasteners [12,13]. The reservoir itself is made of stainless steel.…”

Section: Flight Experiments Setup and Instrumentationmentioning

confidence: 99%

Transpiration-Cooled Hypersonic Flight Experiment: Setup, Flight Measurement, and Reconstruction

Böhrk

2015

Journal of Spacecraft and Rockets

View full text Add to dashboard Cite

The present paper presents the in-flight measurement of the transpiration cooling experiment Aktive Kühlung durch Transpiration im Versuch (often referred to as AKTiV) flown on the suborbital reentry configuration Sharp Edge Flight Experiment II (often referred to as SHEFEX II). Thermal response of the structure is measured just upand downstream of a cooled sample with a noncooled reference setup on the opposite side of the vehicle. The measurement shows that the heat flux is reduced upon coolant exhaust. The maximum temperature reduction with 87 K is observed on the porous sample, while downstream the sample, the temperature is reduced by 75 K by film cooling. This corresponds to cooling efficiencies of 58 and 42% on the sample and downstream, respectively. The evaluation is supported by the semi-analytical tool HEATS, based on a transient heat balance at the surface. Comparison of the results with HEATS shows that the heat flux predicted with HEATS is in good concurrence with the measured temperatures on the cooled sample, as well as upstream and downstream with a maximum deviation by 14%. The analysis suggests that the flow condition around the sharp-edged, faceted vehicle remained laminar longer than expected. Nomenclaturem M = Mach number, -_ m = mass flow rate, kg∕s Nu = Nusselt number, -Pr = Prandtl number p = pressure, Pa R = gas constant, J∕kg · K Re = Reynolds number, -r = recovery factor, -_ q = heat flux, W∕m 2 St = Stanton number, -T = temperature, K t = time, s u = velocity, m∕s α A = heat transfer coefficient, W∕m 2 · K α V = heat transfer coefficient, W∕m 3 · K ϵ = emissivity, -η = cooling efficiency, -κ = isentropic coefficient, -λ = thermal conductivity, W∕m · K μ = dynamic viscosity, Pa · s ρ = density, kg∕m 3 σ = Stefan-Boltzmann constant, W∕m 2 · K 4 ϕ = porosity, -Subscripts C = at panel C c = coolant cond = heat conduction conv = heat convection F = film HG = hot gas p = at constant pressure r = recovery rad = radiation res = reservoir S = surface x, y = coordinates W = wall 0 = plenum ∞ = ambient

show abstract

“…3. The fastener was tested already in a fatigue load environment with good results, however, these tests were carried out with a dedicated fixture which is not representative of the actual TPS assembly 6 . The SHEFEX II vehicle ready for launch is shown in Fig.…”

Section: Typical Cmc Tps Designmentioning

confidence: 99%

Lifetime Testing of a CMC TPS under Vibration Load

Reimer¹,

Kuhn²

2015

20th AIAA International Space Planes and Hypersonic Systems and Technologies Conference

View full text Add to dashboard Cite

A ceramic matrix composite thermal protection system test article was subjected to a dynamic load environment to determine its lifetime. The test article consisted of one panel made from the ceramic matrix composite and the corresponding structural items to mount on a substructure. Special attention was given to the fasteners which were also designed and made from the ceramic matrix composite. An elastic foam material was included between panel and carrier structure which is representative of a flexible high-temperature insulation. The setup is representative of the design that was developed for re-entry vehicles like the SHEFEX I and II flight experiments. A mechanical random vibration load was defined typical of the acoustic loads present around a hypersonic flight vehicle in a turbulent boundary layer. The tests were carried out on a shaker in one direction perpendicular to the panel surface. A total test time of 100 hours was accumulated without noticeable degradation of the fastener performance or the other test items. NomenclatureC/C = Carbon/Carbon C/C-SiC = Carbon/carbon-silicon carbide CFRP = Carbon fiber reinforced plastic CMC = Ceramic matrix composite DLR = Deutsches Zentrum für Luft-und Raumfahrt RTM = Resin transfer molding SHEFEX = Sharp Edge Flight Experiment TPS = Thermal protection system

show abstract

Dynamic Qualification of a New CMC Fastener

Cited by 8 publications

References 0 publications

Joining Techniques for Fibre Ceramic Structures

Joining Techniques for Fibre Ceramic Structures

Transpiration-Cooled Hypersonic Flight Experiment: Setup, Flight Measurement, and Reconstruction

Lifetime Testing of a CMC TPS under Vibration Load

Contact Info

Product

Resources

About