Patent ID: 6718820
Filing Date: 2004-04-13
Classification: G01N

Abstract:
An apparatus for indentation test which measures load and displacement of test materials, comprising:a load applying device comprising a AC servo motor, a reduction gear located below said motor and connected to said motor, a coupling located below said reduction gear and connected to said reduction gear, a connecting axis located below said coupling and connected to said coupling, bearings located around said connecting axis, and a ball screw located below said connecting axis, wherein said load applying device is adapted to transform power from said AC servo motor into a load applied to said test materials, said coupling being adapted to transport power generated by said motor to said connecting axis, said bearings supporting a the rotation movement of said connecting axis, and said ball screw being rotated by said power generated by said motor; a load delivery device for transforming power generated by said load applying device to a vertical load for applying a load to said test materials, said load delivery device being compressively combined with a ball screw nut which in turn is combined with said ball screw whereby to create a supporting axis guiding said load delivery device in said load delivery device; a load sensing device including a deformation gauge attached to said load delivery device by a screw for continuously measuring load applied to said test materials, wherein said load applied is performed by measuring a changed current due to a resistance change of said deformation gauge in proportion to a load applied to said test materials; an extension axis located below said load sensing device in which a male screw located at an upper end of said extension axis is combined with a female screw located at a lower end of said load sensing device; an indenting device located at an end of said extension axis and connected to said extension axis for applying a contact load to said test materials, said indenting device comprising an indenting device holder and an indenting tool combined as a single unit; a displacement sensing device located below and parallel with said indenting device for measuring displacement of said indenting device; a bracket attaching said extension axis which is connected to said indenting device via a connector which is connected to said displacement sensing device; a horizontal moving device for moving a main body including said indenting device in a horizontal direction relative to a fixed main body base; a main body base for supporting said main body; and a programming device connected to said main body for controlling said apparatus to advance said indenting device to a starting point to said test materials, apply a load to said test materials at a predetermined loading rate and for a predetermined indentation displacement, remove said load by moving said indenting device vertically upward according to a unloading ratio, measure indentation load and indentation displacement during load applying and load removing, repeating indentation load and indentation displacement measurements during repeated load applying and load removing cycles, removing said indenting device from said test materials, and drawing a indentation load-displacement curve based on said measurements.