| Recently, along with development of power transmission line, more and more angesteel transmission tower structure is used in Engineering, Thus angle steel K-joints with anode plate type is widely used in the transmission tower structure. But now there is noresearch on connection stiffness of the semi-rigid joint in the transmission tower,transmission tower design in general were assumed to be connected to either pinned orrigid connection which can not reflect this connect really,In the actual situation, thetransmission tower joints should be considered as semi-rigid joints mostly. It is necessaryto make research on the semi-rigid joints,clear the stress condition and various factorswhich influence the stress condition, guide the engineering design in the future to achievesafety and economic balance principle better.①Experimental study. Experimental study is the most direct and effective way inthe research of semi-rigid joints. First,the article combines the UHV transmission projectin the construction of our country,do a full-scale test to the actual presence of K typejoints, two limbs of the K-joints are respectively tension and compression.In the test,theangle steel strength grade is Q420, there are five groups of test,the behaviors of joints isstudied in condition of different eccentric distance,different thickness of jointplate,different bolt numbers and different bolt space,the joints failure mode and the initialflexural stiffness is got.②Finite element analysis. Based on the experiment results,general finite elementanalysis software ANSYS is used to establish the finite element model,then comparativeanalysis of experiment results and finite elment results is made, show the reasons for theerror in finite element results, the conclusion is the finite element model can be used forsemi-rigid joints parameters analysis. Finally，a number of finite element calculationsand parameter analysis are made by the high strength ange steel K-joints,the analysisresult is in the follow:The width and thickness of main angle can increase angle shearingstiffness,but the effect to joint flexural stiffness is very little. Usually, increasing anglestee width cannot improve ultimate flexural bearing capacity of the joints,whileincreasing angle thickness can cause the ultimate bearing capacity of the joints improve.Bolt diameter and spacing have little effect on the joints flexural stiffness,but they canimprove the ultimate bearing capacity of the joints partly. The eccentricity changes havelittle impact not noly on the joint stiffness but the ultimate bearing capacity.If the plate of the joints is enouph to ensure that the plate doesn’t destroy earlier than the joint,thethickness change of plate has almost no effect to the joints stiffness and ultimate bearingcapacity.③Proposed model. According to the test and the results of finite element analysisinthis paper, Contrast the results with the theoretical model, Give a Suggestion that themoment-rotation curves of semi-rigid joints in UHV Transmission Tower can useKish-Chen Three-Parameter Power model,then Study on the effect of shape factor n bythe changes of various parameters.Finally, contrast multiple group finite analysis resultand fit out the shape factor n, The value of n is1.5to2.2. |
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