Stress Relaxation Testing Machine WSC Series │ WNJ-200~500 2 HUALONG WSC Series is used to determine stress-relaxation of metal, such as pre-stressed concrete strand, pre-stressed concrete bar, steel rope and so on., the specimen is deformed a given amount and decrease in stress is recorded over prolonged period of exposure at constant elevated temperature. EN10391:2003 stress relaxation test method of metal and ASTM E32802(2008) Standard Test Methods for Stress Relaxation Tests for Materials and Structures. Automatic draw the real time curve of residual stress versus time, temperature versus time and relaxation rate versus time. Automatic calculate 1000 hours stress relaxation rate of the specimen. The calculation method has double logarithm option and single logarithm option and calculating data has entire data option and data at certain time option. High precision temperature recorder attached to record the influence of room temperature variations in the force curve. Servo-controlled drive system ensures the high precision load/displacement close-loop control, besides, it has a very low noise during the whole test. Loading speed could be set arbitrarily. Constant load and constant displacement control could be selected. Automatically calculate stress relaxation properties of the specimen and print complete test diagram. Realize digital calibration of load quickly and accurately, and has over-load protection function. The coordinate of the curves can be automatically adjusted. When the test begins, the system will automatically adjust the coordinate value. During the whole test process, the curves remain complete. The test requirements can be automatically stored, derive and reset. Data acquisition: After the test the data can be acquired on the test curves through mouse pointer. Optional patent calibration system is mounted on machine to calibrate not only the load cell but also the whole system without disassembly the load cell from machine. Optional dual strain gauge could be introduced into machine for constant strain rate constraint.

Relaxation test data are necessary when designing most mechanically fastened joints to assure the permanent tightness of bolted or riveted assemblies, press or shrink-fit components, rolled-in tubes, etc. Other applications include predicting the decrease in the tightness of gaskets, in the hoop stress of solder less wrapped connections, in the constraining force of springs, and the stability of wire tendons in pre-stressed concrete. The ability of a material to relax at high-stress concentrations such as are present at notches, inclusions, cracks, holes, fillets, etc., may be predicted from...

Host Computer The test software is installed on host computer, this software is characterized by brief interface and convenient operation with powerful function of data processing. It can draw real-time curve and has function of overload protection to prevent Slave Computer Each module is prepared adopting bus technology. The module has high reliability and it is easy to maintain. Load amplifier module The AC amplifying technology is adopted. The measurement error resulted from temperature drift can be avoided. The amplifier can be zero adjusted automatically and calibrated automatically. The...

Technical Specifications Model Load Capacity Measuring Range Load Resolution Load Accuracy Creep of load cell Position Accuracy Horizontal Span Ball Screw Stroke Loading Speed Temperature Accuracy Specimen Dimensions PC Strand PC wire PC Bar Machine Dimensions Gross Weight Load Measurement Accuracy: ±1% of reading to 1/100 of load weighing system capacity meets or exceeds the requirements of the following standards: ISO 7500-1, EN 10002-2, ASTM E4, JIS B7721. Speed Accuracy: Set speed 0.05% Max. Speed: ±1% Set speed ≥0.05% Max. Speed: ±0.5% Position measurement accuracy: ±0.01% of reading or...