Shear Frame With Articulated Joints For Composite Testing
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Solution Overview
Problem
Existing methods for determining the mechanical properties of materials, particularly composite materials, are insufficiently precise and often require complex setups for applying shear loads, which can be costly and ergonomically challenging.
Innovation Solution
A shear frame and testing device with two frame halves that allow for force-fitting and form-fitting fixation of test specimens, featuring articulated joints with only one rotational degree of freedom, enabling precise application of shear loads without connecting the frame halves at the joints, allowing material to be positioned between joints for even edge zone exposure, and a connecting element for transmitting forces using articulation bolts and piston-cylinder units.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If conventional shear testing devices with connected frame halves are used, then structural stability is improved, but device complexity and cost increase
Solution Approach 1:
The frame is divided into two separate frame halves that are not connected at the joints. Each frame half contains its own joints within its structure, creating modular independent units that can be positioned and secured separately while maintaining structural stability during testing.
Solution Approach 2:
A positioning device acts as an intermediary between the two frame halves, enabling precise positioning and secure connection of the frame halves without direct mechanical connection at the joints. This mediator ensures structural stability while keeping the frame halves independently configurable.
2Strength
If joints of frame halves are connected directly, then structural rigidity is improved, but ease of operation deteriorates due to difficulty in positioning test specimens
Solution Approach 1:
The frame structure is segmented into two independent halves with separate joint systems. This segmentation allows each frame half to be positioned and adjusted independently, making it easier to insert and position test specimens between the frame halves without dealing with a fully connected rigid structure.
Solution Approach 2:
The positioning device serves as an intermediary mechanism that facilitates the connection and positioning of frame halves. It enables operators to easily position test specimens and secure the frame halves without requiring direct manual manipulation of the joint connections themselves.
3Volume of moving object
If joints are positioned close together, then frame compactness is improved, but measurement precision deteriorates due to inability to position material between joints
Solution Approach 1:
Each frame half contains its own set of joints positioned within its structure. This segmentation creates distinct joint zones in each frame half, ensuring that joints from opposite frame halves do not interfere with each other and allowing test specimen material to be positioned between the joint areas for accurate shear stress application and measurement.
4Reliability
If complex clamping mechanisms are used, then specimen fixation reliability is improved, but loss of time increases due to specimen change time
Solution Approach 1:
The frame halves are pre-configured with positioning features and joint arrangements that facilitate quick specimen insertion. The positioning device is pre-adjusted to accommodate standard specimen dimensions, allowing operators to quickly insert and secure specimens without complex manual adjustments or reconfiguration of clamping mechanisms.
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
Enables simple, cost-effective, and ergonomic application of shear loads to test specimens, allowing for precise determination of mechanical properties with reduced specimen change time by approximately 30% compared to conventional methods.
Implementation Method 1
a connecting element (60) which is connected to a coupling element (22, 24) of a frame half (10, 20) by means of at least one pivot pin (70), wherein the connecting element (60) is configured to be mechanically connected to the push device and to transmit a tensile and/or compressive force exerted by the push device to the frame half (10, 20) having the respective coupling element (22, 24)
Implementation Method 2
each has four coupling elements (21, 22, 23, 24) and four joints with only one rotational degree of freedom, by which the coupling elements are articulated to one another
Data Source
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AI summary
The invention relates to a shear frame (1) for determining at least one property of a test specimen (140) under the influence of a shear load, comprising two frame halves (10, 20) between which a test specimen (140) can be fixed by force and/or form locking, wherein the two frame halves (10, 20) in the fixed state extend essentially in two planes parallel to each other and each has four coupling elements (21, 22, 23, 24) and four joints (25, 26, 27, 28) with only one rotational degree of freedom, by which the coupling elements (21, 22, 23, 24) are articulated to one another. According to the invention, each joint (25, 26, 27, 28) of one frame half (10, 20) is separated from each joint (25, 26, 27, 28) of the opposite frame half (10, 20) along the line of its axis of rotation (40).Furthermore, the invention relates to a testing device for determining at least one property of a test specimen (140) under the influence of a shear load, comprising the shear frame according to the invention; and a method for determining at least one property of a test specimen (140) under the influence of a shear load using the shear frame (1) according to the invention.