Experimental Research And Finite Element Analysis In The Connections Of Portal Frames

The portal frames are extensive used by our country for manufactureing cost less and constructing faster than other building structures.The problems are created at the same time expecialy the connections of beam and column in portal frames. Firstly this article introduce developing situation of portal frame in our and other countrys introduce designing mothods of nodes in portal frames, The stress performance, node stiffness and maxiumun load were influenced by thinckness of end-plate,nature steel ,welding line,bolt strength and constitution of node by reference and rules of nature and foreign learner.The commom structure node with a bolted end-plate thickness of twenty centimeter and the improving structure make a change by appending a armpit in the connection of the beam and column,in order to test and measurement the action of the armpit that the end-plate thickness is only twelve centimeter .The armpit is simple and was welded in the beam and column easily,it can protect the node domain and forms another line of defence when the accidental happened and avoids brittle failure ,The improving structure is better than the common structure in load capacity ;The shearing deformation is smaller than the commen connections ,it restricts the displacement of the end of the beam.the whole portal frame was analysed by software of ansys,we can draw a conclusion that the stiffness is larger and the displacement of the end of beam is much smaller than the the common bolted end -plate connection.We have experiments for the three number of test coupen and introduce the procedure and analyse the performance result of tests ,we tell the dimention and deformation ,test apparatus , instrument assemble and the position of strain gauge . we can draw conclusions from the test result that the stress performance of appending an armpit than the other two coupens .The range of node was protected by appending a armpit,the concentration of stress is smaller than others.the sidesway of the top of the column is smaller .For the armpit deformation is a arc the bolts can be assembled easily and can dilive loads troube free operation.it forms another line of defence when the earthquake happened and avoids brittle failure.The contact area of armpit with beam and column is larger than other armpits,it relieve the stress concentration of beam and column and decrease the possibility of yielding. The connection was jointed by bolt and welded together ,it has the characteristic that large stiffness and good plastic yield and it can coordinate the deformation of beam and column ,The reason for the destructive style of the first component is the displacement too large.We can draw a conclusion that the bolted end-plate armpit arc is better than other connections in stress performance and assemble easily used software ansys and test result .It can be easily used in project widely.