Features of JASTI Dummy Products
Safety of Molded Products
To reproduce biofidelity, JASTI dummies are manufactured using polyvinyl chloride (PVC) for components that correspond to human skin.
To provide flexibility to the PVC and further enhance biofidelity, JASTI manufactures molded products by adding plasticizers and stabilizers, followed by thermoforming.
Since the start of production in 2009, JASTI molded products have used DINA and DINP, which are considered safer alternatives to DOP, as plasticizers. However, as these plasticizers also contain phthalates and potential health concerns, regarding carcinogenicity, JASTI switched to a new phthalate-free plasticizer in 2015.
As a result, JASTI PVC products now offer an even higher level of safety.
Damping Material
The sternum area of the human body in Hybrid III 50th Male and 5th Female dummies is represented by rib steel components made from special steel. To improve biofidelity, damping material is applied to the rear side of the rib steel.
Previously, damping material manufactured by United McGill was specified for this purpose. However, since that material was discontinued, we now use equivalent alternatives.
Through its own development efforts, JASTI uses a low-carbon material that provides performance equivalent to conventional damping materials while being less susceptible to thermal deformation.
The combination of these rib steel components and damping material also enables JASTI to issue Low/High Speed Impact Certification for chest deflection performance.
Features of Rubber Products
Because crash test dummies require biofidelity in their design and manufacturing, many rubber components are used to reproduce properties such as flexion and extension.
The characteristics of rubber products change over time after manufacturing. For this reason, regulations specify certain tolerance ranges for hardness in dummy components.
Based on these drawing specifications, JASTI provides accurately manufactured components with different hardness levels, including Lumbar Spine, Nodding Block, and Knee Flesh Insert parts.
In dummy calibration testing, adjustment and calibration can be performed by combining components and parts with different hardness levels. Please feel free to contact JASTI for further information or to try these components.
Lumbar Spine
The Lumbar Spine is made from rubber-based material and functions as the lumbar region of the human body. By deforming under load, it absorbs impact force and plays a role in absorbing thoracic impact.
The performance of the Lumbar Spine requires not only surface hardness, but also repeatability, recovery characteristics, and durability.
In particular, the Hybrid III 50th Male requires surface hardness evaluation, while the Hybrid III 5th Female requires a Torso Flexion Test. Chest deflection characteristics are greatly affected and limited by fundamental calibration components such as the Chest Jacket, Rib Assembly, and Lumbar Spine.
For this reason, the accuracy of each component is essential. In order to ensure the overall reliability of the dummy, JASTI conducts various in-house tests and continuously pursues reliability, durability, and repeatability for each component.
Nodding Block
The Nodding Block is a rubber block incorporated into the Nodding Joint Assembly of Hybrid III 50M, 5F, and 95LM dummies. It is an important component for adjusting neck performance in neck certification testing.
For the Hybrid III 50M, the Nodding Block allows fine adjustment in flexion testing by changing its hardness. This affects not only the maximum neck rotation angle of 64–78° and the time to maximum neck rotation of 57–64 ms, but also the maximum moment of 88.2–108.4 Nm and the time to maximum moment of 47–58 ms.
It has been verified that the flexion and extension characteristics of the neck can be adjusted through the combination of neck components and the hardness of the Nodding Block.
According to regulatory drawing specifications, the hardness of the Nodding Block is specified as 80–90 on the Durometer Shore A scale.
JASTI supplies neck assemblies that pass neck certification testing when combined with a Nodding Block of intermediate hardness, Shore A 85. However, if the neck test performance does not meet the required calibration values, adjustment can be made by using Nodding Blocks with different hardness levels.
JASTI offers five different Nodding Block hardness levels: 80, 82, 85, 87, and 90. Before replacing the Neck or molded components, JASTI recommends checking the neck characteristics by adjusting the Nodding Block.
For detailed performance characteristics, please contact JASTI.
Knee Flesh Insert
In knee certification testing, an impact test using a probe is performed to verify whether the dummy structure can properly measure the impact force applied to the knee during a frontal vehicle collision.
The required maximum impact force is 471.5–578.2 daN. A rubber Knee Flesh Insert is installed between the Knee Flesh and the Knee Cap Assembly, and the impact force can be adjusted by changing the hardness of this insert.
According to regulatory drawing specifications, the required hardness is 40–50 on the Durometer Shore A scale. JASTI provides a Knee Flesh Insert with an intermediate hardness of Shore A 45 as the standard specification.
If the required impact force cannot be achieved during performance verification testing, adjustment can be made by changing the hardness of the Knee Flesh Insert.
JASTI offers three types of Knee Flesh Inserts: Shore A 42 soft, Shore A 45 standard, and Shore A 47 hard. If the required values cannot be met in knee impact testing, JASTI recommends trying Knee Flesh Inserts with different hardness levels.
