Company VictoLab Services Presentation VKRT 2013

Transcription

1 Company VictoLab Partner in Product Development on request, specialized in rubber material and modeling. From an idea of a customer until a validated product. All steps of the product development process, including concept development, engineering, prototyping, IP development, assistance in mould development and validation. An important contribution can be assistance in trouble shooting in the existing development projects. Services Concept Development Each problem has more than one solution. The only way to know if you are working on the right solution is to look at the alternatives and make the right choice. VictoLab can generate alternative solutions for your design challenge and help you to make the right choice. Engineering A concept has only value if it meets the requirements, if it leads to a product that can be produced and assembled. From the earliest stage of concept development VictoLab keeps an eye on the requirements that large volume production brings along. FEA When first things right becomes the norm of a successful product development, modeling a product has become an essential step to achieve it. Especially for rubber products where the material properties will be of a great influence to the product performance and behaviour. Therefore Victolab uses different methods of simulation, such as Finite Element Analysis (FEA, Abaqus CAE) and Computational Fluid Dynamics (CFD) to provide an overall insight of the working principle and therefore providing the know-how of your system. During FEA simulation the rubber material properties are translated into useable FEA data (Hyperelastic material behavior). This material fitting is an important step to make sure that the outcome of the simulation is valid. Material Selection It is important in the early stage of design to examine the full materials menu, not rejecting options merely because they are unfamiliar. Victolab can choose the right material for every concept, an essential step in Product Design. 3D Printing Designs Victolab knows the technology to make 3D Printing Designs that meet your requirements. Most products are not designed for 3D Printing, Victolab designs your product to be suitable for 3D printing. Prototyping VictoLab knows the technology to make prototypes that meet your expectations. This will get you the information that you need in every stage of the product development process. VictoLab also knows where to get them quick at the right price. Validation To know you are right is one thing; to be able to prove it is better. VictoLab helps to set up the requirements and assists in the testing and validation process. From concept to validated product. IP Development A patent protects your market from competitors. VictoLab can assist and advice in the process of filing a patent which will secure your future profits. Presentation In the lecture we will walk through all difficulties during the Validation phase. A phase which is very interesting because all disciplines of Rubber Material and Product Development will be challenged. The goal is first things right, so it is just a test phase isn t it?

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3 Product and Material Modeling Victolab VKRT Material Modeling Case: How to use measured data

4 VictoLab Company Profile Product Development on request Rubber Material and Product Modeling Young team with enthusiastic, creative and engineering professionals > 20 years experience Independent partner with network in plastic & rubber

5 VKRT Meten is weten How to use the data e.g. for validation or to generate material / product know-how.

6 Material Modeling Rubber behavior: Little compressibility compared to their shear flexibility Nonlinear Elastic response up to large strains Which material property is needed for rubber modeling? Depends on the function of the product.

7 Material Modeling What to describe: Hyperelastic behavior (large strains) Viscoelastic behavior (rate-strain-dependent) Mullins effect (stress softening / damage)

8 Material Modeling Experimental tests for Hyperelasticity:

9 Material Modeling Input for Viscoelasticity: Creep test data Relaxation test data Frequency-dependent data obtained from sinusoidal oscillation experiments (DMTA) Temperature effects should be included

10 Material Modeling Input for Mullins effect: Experimental unloading-reloading data

11 Material Modeling Experimental data Describe material behavior Describe the unacceptable difference Describe stable material model Approval step Design Test Model in FEA Simulate the test data Compare the Experimental and the simulation data Validated Material Model from experimental data

12 Case: How to use measured data Material data: Uniaxial stress strain relation ISO 37 Tensile Stress - Strain ISO 7743 Compression Stress - Strain Compression set ISO 815 Permanent deformation

13 Case: How to use measured data

14 Case: How to use measured data Uniaxial stress strain relation Nominal Stress Strain relation or True Stress Strain relation

15 Case: How to use measured data

16 Case: How to use measured data ABAQUS FEA Hyperelastic modeling: Data input is : Nominal Stress Strain relation ABAQUS FEA Elastic modeling Data input is : True Stress-Strain relation

17 Case: How to use measured data ABAQUS FEA Hyperelastic modeling: Strain energy potentials Polynominal form (polynominal, neo-hookean, Mooney-Riflin, Yeoh) Ogden form Arruda-Boyce form Van der Waals form

18 Case: How to use measured data Curve Fitting

19 Case: How to use measured data Curve Fitting - 2

20 Case: How to use measured data Experimental data Describe material behavior Describe the unacceptable difference Describe stable material model Approval step Design Test Model in FEA Simulate the test data Compare the Experimental and the simulation data Validated Material Model from experimental data

21 Case: How to use measured data Validate Hyperelastic Material Model: Testmodel ISO 37

22 Validated model from experimental data.

23 Case: How to use measured data Compression set ISO 815 Permanent deformation 168h 200C = 22% 168h 150C = 16%

24 Material Modeling Experimental data Describe material behavior Describe the unacceptable difference Describe stable material model Approval step Design Test Model in FEA Simulate the test data Compare the Experimental and the simulation data Validated Material Model from experimental data

25 Design test model in FEA

26 Design test model in FEA Initial

27 Design test model in FEA Compress RT

28 Design test model in FEA Compress 200C 168h

29 Design test model in FEA Compress RT

30 Design test model in FEA Release CPS=0%

31 Design test model in FEA Test specimen is compressed uniform 25% (if surface is frictionless) Due to heat up Expansion Coefficient is needed. Expansion gives Higher stresses Higher tension strain No change in compression strain CPS calculated = 0% is not correct. Introduce Stress relaxation Introduce Permanent set

32 Material Modeling Experimental data Describe material behavior Describe the unacceptable difference Describe stable material model Approval step Design Test Model in FEA Simulate the test data Compare the Experimental and the simulation data Validated Material Model from experimental data

33 Design test model in FEA Initial

34 Design test model in FEA Compress RT

35 Design test model in FEA Compress 200C 168h

36 Design test model in FEA Compress RT

37 Design test model in FEA Release CPS=21%

38 Validated model from experimental data. CPS Measured Calculated 168h/200C 22 % 21 % 168h/150C 16 % 17 % Material model is useable at deflection rates of 25%.

39 Need for more test data: Compression strain levels from 0.05 till (5% till 50%) Temperature from RT till 200C The different compression strain levels will generated different stress levels for relaxation and damage.

40 Use the material model. Seal performance of an O-ring

41 Use the material model. CPRESS is used to calculated the seal function. Product validation is needed to optimize this FEA model.

42 Summary: Material validation is very important during simulation. Only validated material models can be used in product simulation. During material modeling you (might) have to introduce new tests. Do not use FEA software as black box, prefer to simplify if you do not understand. Ask Victolab

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