Stiffened fairings

Stiffened panel designs. Stiffened panels are exterior fairing panels that are attached on three or four sides. They carry little to no structural loads they are designed primarily to take air loads. Early designs using simple riveted concepts were heavy and prone to rapid sonic fatigue. 

Thermal black Soft carbon black formed by the decomposition of natural gas (e.g., MT, medium thermal black). It has little stiffening effect, but imparts toughness, resilience, good resistance to tearing, and fair abrasion resistance. 

The principle is fairly plain, even an old one. In 1939, the active ingredient of curare—an ancient plant toxin weapon still in use by Indians—was isolated for the first time. In 1943, it was introduced successfully into anesthesiology. Curare provided adequate muscle relaxation without the depressant effect of deep anesthesia induced by ether or chloroform. Over the last 20 years, physicians have used curare to ease the stiffened muscles caused by polio and to treat such diverse conditions as lockjaw, epilepsy, and cholea (a nervous disorder characterized by uncontrollable muscle movements). Eventually, more effective treatments were found for these illnesses, but the active ingredient of curare, d-tubocurarine, led to the skeletal muscle relaxant Intocostrin, which has been used in surgery ever since. Synthetic analogs of d-tubocurarine are used tens of thousands of times per day in the operating room [309]. 

The simulation of the one-ply composite shows that the post-critical assumptions and the simple modelling procedure work fairly well — Figme 2.9. Hence, this approach can be used further for simulation of the four-ply laminate. A slight stiffening response of the material at the end of the test is probably caused by straightening of the yams in the loading direction, which has not been accounted in the model. 

Thermoplastic adhesives are not ordinarily recommended for use at above 66°C, although they can be used up to 90°C in some applications. These materials have poor creep resistance and fair peel strength. They are used mostly in stressed joints and designs with caps, overlaps, and stiffeners. The materials most commonly bonded are non-metallic material, especially wood, leather, plastics, and paper. With the exception of some hot-melt adhesives, thermoplastic adhesives are not generally used for structural applications. Examples of thermoplastic adhesives are shown in Table 4.2. ... 

Thermoplastic adhesives soften and melt when heated (provided that they do not decompose). In other words, they do not cross-link during cure. These adhesives are single-component and harden upon cooling by evaporation of a solvent or water vehicle. They have poor creep resistance, fair peel strength, and are used mostly in unstressed joints and designs with caps, overlaps, and stiffeners. The most common application is to bond nonmetallic materials such as wood, leather, cork, and paper.In general, thermoplastic adhesives are not used for structural applications or at temperatures above 66°C (150°F). Thermoplastic adhesives includeit t ... 

Stiffened Panels These designs refer to exterior fairing panels, which are attached on several sides but, essentially, only carry air loads. The initial riveted design was heavy and suffered badly from sonic fatigue. The design of the first bonded replacement used beaded double panels but these proved to be difficult to bond accurately into place and, perversely, they reduced the overall stiffness of the panel. 

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