Electrochemical Strain Grid Marking Moving Marking Technology Forward

Strain Grid Marking Equipment Strain grid marking has become, over the years, the standard method for analysing stress in sheet metal forming. We manufacture two power units capable of producing the large, geometric patterns required for analysis. These patterns are laid down directly on to the surface of the sheet, prior to forming, by oxidising the material with electro-chemistry. This process is favoured, due to the ease of marking and speed of operation. More importantly however, the process is stress free, and ` forms a permanent mark without compromising the structure of the material. Most...

Mains cable and plug appropriate for country of use 1L of ME8 non-neutralising electrolyte for ferrous metal marking lL of ME5 electrolyte for non-ferrous metal marking lL neutraliser for ME5 electrolyte ME3000TSG. This machine gives a 20amp output and is suited for relatively small strain grid applications, typically 100mm wide marks. The marking output can be set for continuous output, or timed. The machine is supplied in a high quality wooden instrument case with all accessories required for marking including four strain grid stencils. The kit also contains stencil paper and an HM5 hand marker...

Universal Marking Systems Application Information This technique is used in many press-shops to reduce the time and costs of die try-out and to transform press trouble-shooting from a series or random guesses into logical process. The rudiments of this approach are described here. Why circle grid analysis? In sheet metal forming we are looking at the permanent plastic deformation of sheets by stretching, usually, in a complex way. If the sheet is marked in a nondirectional pattern (circles) then any deformation can be measured. If the pattern were, for example, squares, then fruitful measurements...

that of 0.1” or 2.0mm diameter circles, close but not touching, in arrays of four, delimited in a square matrix for easy identification. Other patterns approximating this concept are also acceptable. Summarising at this stage: to be able to identify regions of high strain is useful in itself, but stain measurements from deformed small-diameter circles can provide far more useful information. Firstly, we must consider both major and minor strains. For a given major strain, e1, the minor strain e2, can be positive, zero or negative. This is illustrated in figure 3. The point of supreme importance...

Major Strain It is often instructive to represent the strains in a panel by a plot of major values taken in the critical area shown in figure 6, with the values approaching a ‘ ceiling’ - this will be the minor strain limit from the FLD. Assume for a moment that this is a die- try out situation. It is now possible to see how close a successful pressing is to failure. If too close then action should be taken before putting tools into production. Only critical circles shown Figure 6. Severity point - how near is the part to failure? Take now a production splitting problem represented in figure...

Marking Information The Universal Marking Systems strain grid marking equipment can be used on ferrous and nonferrous metals, producing either an oxide or etched mark on the test piece. The marking process is quite simple and fast and is ideal for on-site testing. It is important to follow the instructions of the equipment and solutions being used. Please contact us or your local Agent or distributor for copies of our product sheets. Ferrous metals. There are a number of electrolytes that can be used, but ME8 is good choice due to its nonneutralising properties. It will produce a good dark oxide...

neutralising solution (MN1 for ferrous metals or MN4 as an immersion neutraliser or MN2 for non-ferrous metals). Press or form the test piece and measure the results. Measuring the results. The simplest way is to use our Universal Marking Systems Mylar rules. These are graduated in the percentage of stretch of the circle. Optical measuring systems are also available.

Universal Marking Systems Strain Grid stencil sizes Universal Marking Systems Strain grid stencils are produced in three standard sizes. Pattern style.

3/4 inch squares with 1 inch circles

0.1 inch circles in 0.25 inch squares O.linch circles

5mm circles 5mm circles with 2.5mm squares

0.1 inch circles 0.1 inch circles 0.1 inch circles 10mm circles in 5mm squares 13/64 inch circles in 1/2 inch squares 5mm circles with 2.5mm squares 10mm circles with 5mm squares 2mm squares 5mm circles in 12.5mm square 1mm circles 5mm grid – special 50mm x 50mm pattern size 5mm grid – special 50mm x 35mm pattern size 2.5mm grid – special 50mm x 50mm pattern size 2.5mm grid – special 50mm x 35mm pattern size 5mm circles As above As above As above Please note: Maximum width of strain grid stencil now available is 300mm It is possible to manufacture additional grid designs. Please submit specification...

Strain grid stencils for ME3000TSG strain grid marking kits Strain grid ref. No. SG77A SG77B SG77C SG77D Marking size Stencil size Pattern style 6mm circles 2.5mm circles 5mm circles 2.5mm circles in 6mm squares Stencil size Marking size Universal Marking Systems Ltd. Head Office: Mount Road, Feltham, Middx. TW13 6AR. ENGLAND Sales - Tel. 020 8898-4884/5 Fax. 020 8898-9891. e-mail: [email protected] www.ums.co.uk