Mod­u­lar per­for­mance test bench for force-dis­place­ment measurements

Tar­get

In the scope of a mas­ter exam at the tech­ni­cal col­lege in Aachen a test bench for force-dis­place­ment mea­sure­ments was built up at the com­pa­ny Qual­i­ty Automa­tion. The project should pro­vide a basis for inves­ti­ga­tion regard­ing the impact in case that mate­ri­als are loaded with forces. Max­i­mal veloc­i­ties should be detect­ed in which case a force mea­sure­ment can take place.

In the today’s man­u­fac­tur­ing often process­es are applied in which dif­fer­ent mate­ri­als are treat­ed under influ­ence of forces, e. g. con­nect­ing process­es, mate­r­i­al weld­ing under pres­sure or endurance testing.

The test bench

The test bench con­sists of an EMC-cylin­der of the com­pa­ny Bosch-Rexroth and serves as means for force trans­mis­sion. The force that acts on the test sam­ple is mea­sured by a sen­sor of the com­pa­ny HBM.

To the process: The test sam­ple is fixed on the test bench and a test force in the field from 0–1000N is sim­u­lat­ed by the oper­a­tor. The EMC-cylin­der, dri­ven by a Bosch-Rexroth axis, loads the test sam­ple with the test force. Is a force impact detect­ed by the sen­sor a record­ing of the trav­el­ing dis­tance and the force is start­ed to get a force-dis­place­ment dia­gram. The force reg­u­la­tion was real­ized by the MLD-func­tion of the Bosch Rexroth-axis in that way that a force reg­u­la­tion swapped the inter­nal con­trol cas­cade. The record­ing was done by the axis-inter­nal oscil­lo­scope function.

Result

The stiff­ness of the test sam­ples deter­mines the speed with which die force mea­sure­ments are done. Regard­ing over­load an opti­mal speed must be used depend­ing on the test mate­r­i­al in order to achieve a sat­is­fy­ing result.