Experimental Study On Linear Expansion Coefficient Of Tensional Cable Material

In modern structure, the height and span of building have become a symbol of structure design and construct level. To satisfy the two objective requirements, the prestressed technology has been widely used and developed, especially in modern prestressed steel structure. The cable material which is the core of prestressed steel structure has developed more swiftly, and the structure engineers have become more exigent to exactly master the other basic technical parameter besides strength. So, in this paper, one facet of the cable's basic technical parameter-linear coefficient of thermal expansion is chosen as a research object.Based on extensive investigation and'Parameter Measurement for Metal Materials Thermal Expansion Characteristic Values'(GB/T 4339-1999), the national measurement standards, measurement device of water-heated expansion was developed, according to the cable properties, and feasibility of the device was proved by material calibration of steel wires and steel bars etc…With the water-heated device, measurement of steel wire ropes, steel strands and half-parallel steel wire strands ranged from 3mm~9.3mm to 7×37 were carried out. Test datum was fitted and analyzed through mathematic software ORIGIN, so that the linear expansion coefficient obtained from the test for such materials was more precise for practical application.Finally, the finite element analysis for a beam string structure was carried out according to the linear expansion coefficient, and it is proved that the thermal expansion have an important influence on the practical stress of prestressed steel structures.