Coped Beam Lateral Bracing with Dog-Bone Yield Links
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Solution Overview
Problem
Conventional lateral bracing systems in light-framed constructions fail to withstand repetitive lateral loads during seismic activity and high winds, leading to structural damage and potential collapse, and often require replacement after initial yield or failure.
Innovation Solution
A lateral bracing system with high initial stiffness and energy dissipation capabilities, utilizing buckling-restrained braced devices with 'dog-bone' shaped yield members and a shear tab to resist rotation and vertical shear, along with coped beam sections to prevent interference and binding, allowing for controlled yielding and easy replacement of damaged components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional lateral bracing systems are used, then initial structural support is provided, but the system yields and fails under repetitive lateral loads during seismic activity and high winds
Solution Approach 1:
The lateral bracing system is segmented into replaceable yield links and permanent structural components. The yield links are designed to yield and can be easily replaced, while the main structural frame remains intact. This segmentation allows the system to maintain reliability under repetitive lateral loads by replacing only the damaged yield links rather than the entire bracing system.
Solution Approach 2:
The yield links are designed with specific geometric parameters (dog-bone shape with reduced cross-section) that control their yielding behavior. By changing the parameters of the yield links (cross-section area, length, material properties), the system can be tuned to yield at desired load levels, protecting the main structure while providing reliable performance under repetitive lateral loads.
2Strength
If the lateral bracing system is designed with high strength to resist lateral loads, then structural integrity is improved, but the system becomes complex and difficult to manufacture
Solution Approach 1:
The bracing system is divided into simple, standardized yield links and permanent structural components. The yield links are simple dog-bone shaped elements that are easy to manufacture using standard fabrication processes, while the permanent frame uses conventional structural shapes. This segmentation reduces manufacturing complexity compared to designing a single complex high-strength bracing system.
Solution Approach 2:
The yield links are designed as inexpensive, replaceable components with limited service life (they yield and need replacement). By using simpler, cheaper materials and fabrication methods for the yield links rather than high-strength permanent components, the system achieves the required strength through redundancy and replaceability, reducing manufacturing complexity and cost.
3Adaptability or versatility
If the beam is designed to rotate relative to the column under lateral loads, then flexibility is improved, but clearance issues and binding occur between components
Solution Approach 1:
The interfering portions of the beam flanges are removed (coped) to create clearance for the yield links and allow free rotation of the beam relative to the column. By extracting the material that would cause binding, the system achieves the desired rotation capability while maintaining proper clearances between components during lateral loading.
4Ease of repair
If the yield links are designed for easy replacement, then maintenance is simplified, but the initial structural performance may be compromised
Solution Approach 1:
The yield links are segmented as separate, easily replaceable components connected to the permanent frame through simple connections (bolts or welds). This segmentation enables easy replacement while the overall system strength is maintained through proper design of the permanent frame and connection details that preserve structural integrity during both service and replacement phases.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The system effectively dissipates energy under lateral loads, maintaining structural integrity by providing predictable and controlled yielding, preventing buckling, and simplifying construction and maintenance by allowing for easy replacement of yield links, thus enhancing the durability and safety of light-framed constructions.
Implementation Method 1
a lateral bracing system constructed to provide a high degree of energy dissipation through hysteretic damping
Implementation Method 2
buckling-restrained braced devices with 'dog-bone' shaped yield members
Data Source
AI summary
A construction formed of column and a beam, where the beam has top and bottom flanges coupled to the column by a lateral bracing system, and a web between the top and bottom flanges. The lateral bracing system may include a column-mounted plate including a horizontal portion and a vertical portion, the vertical portion affixed to the column. The beam may be coped at top and bottom edges of the web to prevent binding of the beam flange with the column-mounted plate upon rotation of the beam relative to the column.