Reinforced hats

Soft caps of plastic or leather give protection against chemical splashes, especially when working with overhead pipes, tanks, heat exchangers, and other equipment which may leak. Reinforced hats of metal, laminated plastics, or other materials resistant to impact from falling objects should be worn when overhead work is performed (a properly fitting hat gives maximum protection). 

T. W. HUSEEIf > BELL LABS. conment refers to the previous question (m processibilily, and I wanted to reinforce >hat Frank had said aboxit predicting processl-bill ty from some of these studies. In our own work we have found compositions of FPO and polystyrene in xhich the zero sheau viscosily scales with concentration of polystyrene in a very predictable manner and in ihich the shape of the viscosity-sheaor rate curve also scales in a very predictable manner. 

This paper presents results from a study of assemblies composed of glass fibre reinforced epoxy composites. First, tests performed to produce mixed mode fracture envelopes are presented. Then results from tests on lap shear and L-stiffener specimens are given. These enabled failure mechanisms to be examined in more detail using an image analysis technique to quantify local strain fields. Finally the application of a fracture-mechanics-based analysis to predict the failure loads of top-hat stiffeners with and without implanted bond-line defects is described. Correlation between test results and predictions is reasonable, but special attention is needed to account for size effects and micro-structural variations induced by the assembly process. 

The Pinto s bnmper in 1971 and 1972 was essentially ornamental, and unlike Ford cars produced overseas, the Pinto was not reinforced behind with baffling known as hat sections. Graham, Ibid. 

Using a Jacquard head instead a dobby for shedding opens the possibility to create user-defined curved contours of hollow zones. Curved tubes, fittings having other than 90° angles between the intersecting tubes, helmet and hat shells, as well as similar types of shapes can be created with this method. One of the most spectacular applications is a reinforcement fabric of missile noses (Rothe and Wiedemann, 1963). 

For more than 100 years, people have developed devices and processes to create shell geometries of woven fabrics directly at the weaving machine. Whereas first applications were corsets and hats, later developments were focused more and more on technical textiles. Especially fibre-reinforced materials have accelerated 3D shell fabric progress because processing of the fibre reinforcement as a 3D preform promises cost effectiveness and quality advances compared to 2D fabrics. 

Early aircraft floors were constructed from bonded plywood or, where weight was a significant factor, from metal sheets which were reinforced with top hat stringers, I-beams, channels, etc. these stringers would have been riveted to the skins. 

Hard hats are made of rigid plastic, sometimes with a midline reinforcement ridge. Different styles are available (those made in the form of a traditional cowboy hat are often not permitted on process facilities). 

Where large areas of sheet metal or fibre reinforced plastics are used, it is common to stiffen these by attaching deep sections, either by welding, riveting or bonding. As an example, the top-hat design is... 

The drapeability describes the deformation of a textile fabric under its own weight without external loads. The textile can be deformed three-dimensionally. The term drapeability also stands for the deformability of a textile until the first wrinkles appear. The wrinkle-free deposition of a textile on a spherical body requires a two-dimensional deformability of the textile. A wrinkle would impair the mechanical properties. When producing hats, upholstery, or textiles for the reinforcement of composites, this property is crucial. 

---