Mobile Clamping Bed for Prestressed Concrete Tensioning
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Solution Overview
Problem
The existing clamping frames on circulating pallets for precast concrete elements require large, heavy profile beams to absorb compressive forces, leading to asymmetrical lead passages and increased weight, making them cumbersome and costly.
Innovation Solution
A mobile, self-supporting clamping bed with opposing abutment plates and tension elements that absorb stresses independently, allowing for flexible repositioning and modular use, reducing weight and cost.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If a clamping frame with profile beams is used to accommodate reinforcement strands, then the reinforcement strands can be tensioned to achieve required tensile forces, but the profile beams become very heavy (up to 15 t) and complex due to the need to absorb buckling and bending forces from asymmetrical lead passages
Solution Approach 1:
The clamping frame is divided into separate functional components: abutment profiles for compression, abutment plates for force distribution, and tensioning devices for applying force. This segmentation allows each component to be optimized for its specific function, reducing the overall weight and complexity of the system.
Solution Approach 2:
Instead of having the profile beams absorb both tensile and compressive forces, the invention inverts the approach by using separate abutment profiles for compression and abutment plates for force distribution. The lead passages are made symmetrical, inverting the asymmetrical design that caused bending moments in the traditional profile beam system.
2Force
If large profile beams are used as abutments to accommodate reinforcement strands under prestress, then the required tensile forces can be achieved, but the lead passage becomes asymmetrical in the vertical direction, requiring additional reinforcement and increasing complexity
Solution Approach 1:
The invention applies symmetry to the lead passages, making them symmetrical in the vertical direction. This eliminates the asymmetrical design that caused bending moments and required additional reinforcement, thereby reducing device complexity while maintaining the required tensile force capability.
Solution Approach 2:
The invention inverts the traditional approach by separating the compression function (abutment profiles) from the force distribution function (abutment plates). This functional inversion allows for symmetrical lead passages and eliminates the complexity of reinforced profile beams.
3Stability of the object's composition
If a clamping frame is firmly connected to the circulating pallet, then the structure provides stable support, but it cannot be freely repositioned between different circulating pallets, reducing flexibility
Solution Approach 1:
The clamping bed is designed as a dynamic, self-supporting structure that can be easily assembled and disassembled. The abutment profiles and abutment plates form a stable configuration during use, but can be freely repositioned between different circulating pallets, providing both stability during operation and adaptability for repositioning.
Solution Approach 2:
The mobile clamping bed is self-supporting and does not require firm connection to the circulating pallet for structural stability. The abutment profiles and abutment plates themselves provide the necessary support, allowing the system to be independently repositioned without relying on the circulating pallet structure.
4Manufacturing precision
If reinforcement strands are arranged in the lower foot area of profile beams to be embedded in concrete, then proper embedding is achieved, but the tensile forces act decentralized outside the center of gravity, causing buckling and bending forces that require additional reinforcement
Solution Approach 1:
The system segments the force-bearing functions: abutment profiles handle compression, abutment plates distribute forces, and tensioning devices apply tensile forces. This segmentation allows the reinforcement strands to be properly embedded without requiring the profile beams to absorb additional buckling and bending forces, maintaining both embedding precision and structural strength.
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 mobile clamping bed is statically balanced, enabling efficient transmission of tensile forces without bending or tilting, allowing for more flexible and cost-effective prestressing of precast concrete elements, including ribbed plates and girders with varied reinforcement geometries.
Implementation Method 1
a piston-hydraulic cylinder device
Implementation Method 2
which take up the same tension as, comparatively, the lower reinforcement elements
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The bed (1) has two abutment plates (7, 8) arranged opposite to each other, and abutment profiles (6) arranged between the abutment plates. Prestressed reinforcement cords accommodated in a cross section of prestressed reinforcement, where the cords are arranged in a table form. The profiles press the plates against each other by a clamping device (4) i.e. piston-hydraulic cylinder device. Reinforcement elements are made of strands or wires or rods, and hydraulic cylinders are fastened to an axis of a pressure pipe.