Gabriela Martínez

Recent Patents on Expanded Metal

Expanded metal has been widely used around the world. This paper is aimed at presenting latest advances in the use of expanded metal in engineering. Currently, expanded metal is mainly used in the construction industry as furniture, fences or protection purposes. Hundreds of patents can be found in the literature regarding possible applications for expanded metal. These applications fall into four main areas: furniture, construction, biomechanics, and energy absorption systems. When expanding the metal, the material undergoes slits and stretching modifying the mechanical properties of the base metal, hence enhancing the material strength. Additionally, there is a reduction of the weight per unit of area, which is an asset when designing lightweight structures. Waste material from the manufacturing process is almost none, since the base metal is cut and stretched to the final form. Recently, expanded metal sheets are used in architecture to create modern, efficient and elegant buildings that are also energy-efficient, open and transparent. The relevant patents on expanded metals are discussed.

ENERGY ABSORPTION CHARACTERISTICS OF COILED EXPANDED METAL TUBES UNDER AXIAL COMPRESSION

THIS PAPER PRESENTS AN EXPERIMENTAL INVESTIGATION ON THE AXIAL CRUSHING OF COILED EXPANDED METAL TUBES SUBJECTED TO COMPRESSIVE LOADING. THE INVESTIGATION AIMS AT COMPARING THE ENERGY ABSORPTION CHARACTERISTICS BETWEEN TUBES FABRICATED WITH COILED EXPANDED METAL MESHES AND SOLID PLATES. THEN, A SERIES OF QUASI-STATIC AXIAL CRUSHING TESTS WERE PERFORMED TO OBTAIN THE STRUCTURAL PERFORMANCE ON COILED TUBES, AND THEN COMPARE THESE WITH ROUND AND SQUARE SOLID TUBES. COILED TUBES WERE FABRICATED USING CIRCULAR AND SQUARE GEOMETRIES, AS WELL AS VARIOUS CELL ORIENTATIONS. THE RESULTS SHOWED THAT CELL ORIENTATION ENHANCE THE ENERGY ABSORPTION RESPONSE OF THE COLLIDED TUBES. REGARDING THESE RESPONSES IN COMPARISON TO THOSE OF SOLID TUBES, THE RESULTS SHOWED THAT FOR COILED AND SOLID TUBES WITH THE SAME WEIGHT, THE ENERGY ABSORPTION CAPACITY OF THE FORMER IS MUCH LESSER THAN THE LATTER.

AXIAL CRUSHING OF CONCENTRIC EXPANDED METAL TUBES UNDER IMPACT LOADING

THIS PAPER INVESTIGATES THE AXIAL CRUSHING RESPONSE OF CONCENTRIC EXPANDED METAL TUBES UNDER IMPACT LOADING. THE STUDY IN CONDUCTED BY MEANS OF NONLINEAR FINITE ELEMENT SIMULATIONS, CONSIDERING THE SPEED OF DEFORMATION AND THE SIZE OF THE EXPANDED METAL CELLS. IN THE ANALYSIS, TWO TUBES ARE PLACED CONCENTRICALLY AND THEN AXIALLY CRUSHED WITH AN IMPACT MASS AT VARIOUS SPEED LEVELS. CRUSHING LOAD-DISPLACEMENT RESPONSES ARE ANALYZED TO INVESTIGATE THE INFLUENCE OF THE SIZE OF THE MESH AND THE IMPACT SPEED. THE RESULTS SHOW THAT SPECIMENS WITH THE SAME MESH SIZES INCREASES THEIR CRUSHING LENGTH WITH INCREASING SPEED. FINALLY THE MAIN OUTCOME OF THIS INVESTIGATION IS TO ADD TO THE STATE OF KNOWLEDGE INFORMATION CONCERNING THE USE OF EXPANDED METAL MESHES IN IMPACT ATTENUATION DEVICES.