tailored beforehand for composite materials that opens the door to a new, but according to the design, Software tools are needed to understand this complex process and conduct research.
Design engineering of custom composite preform parts
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using software tools can understand complex preparation von berg systeme design process and to carry out research work
recently developed many composites can shorten the production rhythm and reduce the cost of new technology, which can increase the composite application in the automotive, industrial and consumer goods industry. One of the most promising areas of development is the automated production line, which is used to cut and lay thermoplastic prepreg strips to form custom billets, which are then converted into parts by die molding and injection molding.
actively into the technology development of the company include: Airborne in the Netherlands, Van Wees UD and Crossply Technology in the Netherlands, and R& in Engineering and Advanced Manufacturing in France; T organization Cetim.
Cetim in 2015 launched its Quilted Stratum Process (hereinafter referred to as QSP) Process. Using the QSP process, it is able to produce complex shapes on a production line with a pulse time of 40 ~ 90s. For example, the use of QSP, a molding to L beam Ω Shape profile, is the 13 1.5mm, 2mm and 3mm thick organic sheet (fabric thermoplastic prepreg) patch together with UD belt, integrated into a 6mm thick part, each part of the production cycle time of less than 77s.
thermoplastic composite material parts of high yield production line: Quilted Stratum developed by Cetim The Process (QSP) line integrates the stamping of thermoplastic composites and the secondary molding of short fiber reinforced plastics, Able to produce a variety of low cost, high yield rate of the thickness of the complex shape parts (pictures from Cetim)
however, the use of automation technology, such as QSP Engineers must develop design and optimization methods to be able to evaluate theoretical combinations of many local layers and the corresponding changes that occur in terms of number, thickness, location, and composition of layers (such as the type of reinforcement material and fiber orientation).
with that in mind, Cetim combined its experience in structural analysis, non-destructive testing and manufacturing of composite materials with the expertise of advanced optimization methods used by ONERA (French Aerospace Laboratory) in the aerospace industry for many years, resulting in QSD— — This is a tool now used in Altair Engineering's (Troy, Michigan, USA) HyperWorks Computer Aided Engineering (CAE) software, which is basically an optimization add-on tool that helps design composite parts made using strip - and organic sheet based processes, And controlling their cost, including how production waste can be used to achieve zero-waste, closed-loop manufacturing.
4 step process
QSD method includes four steps: structure optimization, forming analysis, layer identification and analysis from design to cost. These help the designer to quickly test ""what can be done with the input material"" and to make the right decisions about mechanical constraints and production constraints to control the cost of the part.
development with the Altair QSD additional tools, make all HyperWorks OptiStruct user can use it directly in the known environment. These users can use the QSD tool using the in-house technology they have already developed with Altair software, without having to develop new finite element models.
4 steps: QSD software tools and methods developed to optimize parts made of thermoplastic composite strips and organic sheets consist of 4 steps (image from Cetim)
structure optimization
The first step in the QSD process is to select the thermoplastic strip, And enter their properties, including strength, modulus, and other standard parameters, from a Designer's selected database or through Altair's Multiscale Designer database of anisotropic thermoplastic composites and their micromechanical models.
QSD using this database and HyperWorks Optistruct to complete ""stiffness matching optimization.
due to some of the results from this analysis is difficult to imagine (e.g., anisotropic stiffness), so the QSD provided with complex and rich data to interact in a variety of ways, including direct variable fields or interpretation of the results, Such as principal stiffness direction or stiffness polar coordinates.
structure optimization results: QSD structural optimization results can be displayed in a variety of ways, including: (a) direct variable field, (b) principal directional stiffness, (c) rigidity polar diagram (image from Cetim)
all of these show the same mechanical response are defined, But also provide customized views based on the user's selection preferences. The goal is to help designers understand and visualize the way to ""achieve the desired performance of the part."" This step optimizes thickness and weight, resulting in a 50% reduction in weight compared to metal parts.
forming analysis
The next step is to help designers use the Drape Estimator tool to first expand the 3D shaped parts into 2D drawings, and then use the clustering algorithm to automatically partition the 2D drawings. The goal is to easily and quickly evaluate the connection between the flat preform and the finished part.
by car beam as an example, based on finite element mesh and results from the OptiStruct, the original will be divided into 300 districts, 2 d drawings by QSD forming analysis, reduced the number of partitions to five.
forming analysis: QSD forming analysis first flatten the parts, then use the clustering algorithm to divide the parts, and then simplify these regions, so that the number of regions from 300 to 5, To improve manufacturability (image from Cetim)
then, Designers can then straighten and flatten the edges of each zone to minimize the waste associated with the corresponding cut layer, a key step in controlling costs and improving production viability.
this step is also very interesting, because the designers can evaluate layer and shape simplified mechanical properties of parts. If a compromise needs to be made between mechanical properties and the manufacturability, scrap, and cost of the part, this step provides the data for this evaluation.
layer identification
the goal of this step is, By selecting from a QSD overlay database or a layer database that can be enriched with customer-specific data, you can determine the best local overlay for each zone.
QSD tools to help designers to draw and test parts of layer, and then through mechanical standard (such as local displacement, buckling coefficient or eigen frequency) to assess the response of the parts to find the best layer strategy.
layer identification: In the process of paving identification, the layers on the flat pre-formed parts are optimized to avoid waste products, And can test layer scheme to determine the best solution (image from Cetim)
from design to cost analysis
As a final step, designers can assess the material cost of the part, including the cost of scrap due to cutting and combining the layers and the cost of manufacturing. In fact, the number of layers laid and the amount of material wasted per layer are major cost drivers.
the rapid assessment results of waste can be found in the QSD soon, so that they can use in the early design iterations evaluation value.
for the final iteration, each layer can be exported, to take advantage of the user like any software detailed analysis of the nested. Parameters can also be customized by the designer, if desired, to be used in the component cost estimation formula, so that the designer can evaluate various layup schemes and compare them in terms of waste, manufacturability, cost, and mechanical properties.
it is worth mentioning that QSD tool to assess the use of all kinds of semi-finished products, such as strip and fabric, or cross lay out of organic material. It can also evaluate recycled materials such as nonwoven felt made with recycled Carbon Conversions, ELG Carbon Fibre and others, or Thermosaï from Cetim; c technology or other similar processes, thermoformable sheets made from thermoplastic waste.
of course, must ensure that this kind of material mechanical properties, but once established, can easily to input them to the QSD modules, including the final layer of library/laminated database. In this way, the waste generated by the parts can be reused back into the parts for a closed loop manufacturing with zero waste. — This is the ideal goal for all sustainable composite manufacturing.
can increase the application of composite tool
QSD is suitable for the first step of the design process, as it is suitable not only for Cetim's QSP process, but also for all processes used to manufacture custom preformed parts, regardless of the degree of automation (e.g., automated strip laying, automatic cutting, manual layup, etc.). Its purpose is to help engineers optimize parts so that bad design choices can be avoided early in the design process.
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