Buckling-restrained diagonal brace using lapping and improved plugging connection

Abstract

A buckling-restrained diagonal brace is provided. The buckling-restrained diagonal brace mainly contains a core element and a restraining element. The core element is an assembly of a specific number of steel members having a specific shape whose cross-sectional dimension is determined based on the load requirement. The core element has a larger cross-section at the ends than at its medial section. The core element is encased in the restraining element. The restraining element manly contains a single or multiple steel tubes filled with concrete, mortar, or reinforcing members. The restraining element is to protect the core element so that it wouldn't be buckled and destructed under load. By using a lapping or an improved plugging type of connection to a structure frame, the buckling-restrained diagonal brace is able to yield steadily when loaded in both tension and compression and the buckling-restrained diagonal brace would have a full hysteretic curve. The buckling-restrained diagonal brace has a significantly enhanced ductility and energy dissipation capability, and is able to reduce vibration and to lower seismic impact.

1 . Buckling-restrained diagonal braces using lapping and improved plugging types of connection, comprising a core element and a restraining element, said core element being an assembly of steel members having an arbitrary and symmetrical cross-sectional shape, said core element having a larger cross-section at its end than at its medial section, said core element encased in said restraining element, said restraining element being a casing assembled by at least one steel tube member filled with one of concrete, mortar, and reinforcing members, said core element restrained by said restraining element so that said core element would not be buckled and destructed under compression and said buckling-restrained diagonal brace would steadily yield and has a full hysteretic curve so as to increase significantly its energy dissipation capability, to reduce vibration, and to lower seismic impact.  
   
   
       2 . The buckling-restrained diagonal brace using lapping connection according to  claim 1 , characterized in comprising: 
 a pair of independently formed restraining members;    a pair of independently formed core members, each of said core members having a bar shape and a larger cross-section at said core member's ends than that of said core member's media section, each of said core members encased in one of said restraining members respectively, said core members connected to a structure frame using lapping type of connection; and    a bonding plate for bonding said restraining members.    
   
   
       1 . The buckling-restrained diagonal brace using lapping connection according to  claim 2 , wherein each of said pair of restraining members is a steel tube filled with a material selected from the group consisting of concrete and mortar.  
   
   
       2 . The buckling-restrained diagonal brace using lapping connection according to  claim 2 , wherein said pair of restraining members are made of pure steel and comprise a steel tube, and steel plate and bolts for connecting said steel tube.  
   
   
       3 . The buckling-restrained diagonal brace using improved plugging type of connection according to  claim 1 , characterized in comprising: 
 a restraining member having at least one steel tube;    a symmetrical core member, said core member having a larger cross-section at said core member's ends than that of said core member's medial section, said core member fixedly locked by end plates at said core member's ends; and    plugging connection plates for connecting said buckling-restrained diagonal brace and a structure frame.    
   
   
       4 . The buckling-restrained diagonal brace using improved plugging type of connection according to  claim 5 , wherein each of said pair of restraining members is a steel tube filled with a material selected from the group consisting of concrete and mortar.  
   
   
       5 . The buckling-restrained diagonal brace using improved plugging type of connection according to  claim 5 , wherein each of said pair of restraining members is made of pure steel, and comprises a steel tube, and steel plate and bolts for connecting said steel tube.  
   
   
       6 . The buckling-restrained diagonal brace using improved plugging type of connection according to  claim 5 , wherein said core element and said restraining element have arbitrary shapes and cross-sections, and are assemblies of an arbitrary number of members.  
   
   
       7 . The buckling-restrained diagonal braces using lapping and improved plugging types of connection according to  claim 1 , wherein said core element is characterized in that said core element is an assembly with a plurality of sections that have different cross-sections respectively and that a medial section has a material strength no greater than that of end sections.  
   
   
       8 . The buckling-restrained diagonal braces using lapping and using improved plugging types of connection according to  claim 1 , wherein said restraining element is characterized in that constituent members of said restraining element are made of a material selected from the group consisting of metallic materials, non-metallic materials, and combinations of metallic and non-metallic materials.