SAE J1051:2020 pdf free

SAE J1051:2020 pdf free.Force-Deflection Measurements of Cushioned Components of Seats for Off-Road Work Machines
TEST CONDITIONS- The specimen shall be conditioned, undeflected, and undistorted at 22 °C±2.8 °C and relative humidity of 50%±2% for at least 12 h before being tested. The tests shall be performed 96 h or more after the manufacture of the raw materials used in the test specimen (foam, elastic components other than metal, etc.). In case of a question, refer to the applicable SAE or ASTM specification (if available) for the particular material.
Mount Specimen- -Mount the specimen with the top surface parallel to and centered with the indentor,unless otherwise specified by mutual agreement of the manufacturer and the customers. The 200 mm diameter curved or flat indentor shall be used on seat and back cushions unless otherwise specified. A light muslin of a quality comparable to a grade described as a weave of 48 threads per inch and density of 190 g/m2 is allowed to prevent marking of the component. In the case of components with unusual shapes or contours, location for placement, and the size of the indentor is to be agreed upon by the manufacturer and customer and shall allow a minimum of 80% of the indentor area to be in contact when the initial zeroing force of 3.2.3.3 is applied. (Example: Smaller diameter or curved indentor for curved backrest-see Figure 2.)
Force-Deflection Application- For the 200 mm indentor, apply an incremental force (no greater than 220 N) slowly to minimize shock. Allow 1 min for the specimen to stabilize, then measure the deflection.Continue this incremental procedure without removing the preceding force until the maximum force of 1335 N for the seat cushion and 665 N for the back cushion is reached. For the 50 mm indentor or thin cushions, incremental deflection versus force may be more desirable. When incremental deflection is used, the specimen shall be compressed to not less than 20% of its original thickness. When the maximum force is 45 N or less the indentor diameter should be increased if possible.SAE J1051 pdf free download.