L14
Coupling / Co-simulation

Back to overview

17:35
conference time (CEST, Berlin)
A Weak Coupling Approach to Calculating the Effects of Electromechanical Interactions in an EV Drivetrain
27/10/2021 17:35 conference time (CEST, Berlin)
Room: L
B. Lukasik (Romax Technology Ltd., GBR); A. Shahaj (Romax Technology Ltd, GBR)
B. Lukasik (Romax Technology Ltd., GBR); A. Shahaj (Romax Technology Ltd, GBR)
With the prevalent move of the automotive industry into electrification, the nature of vehicle powertrain NVH (Noise, Vibration and Harshness) has altered. Therefore, any previous approach to understanding and controlling NVH of the powertrain must now adapt to be applicable to the state of the art in powertrain design for electric vehicles. Electromagnetic excitation is a well-known source of noise in electrical machines and indeed, is likely be a dominant noise source in electric vehicles (EVs) as well as gear meshing excitation. The analysis of noise emission is one that requires a system level approach that accounts for the components that contribute to the noise production (electromagnetic and mechanical) and the resulting vibration transmission. A multifidelity, multiphysics electro-mechanical analysis approach is presented that enables scrutiny of noise producing mechanisms in the EV powertrain at the design stage. Here the authors present investigations into phenomena occurring in the air gap of the e-machine and the effect of these on vibration of the structure. Static eccentricity of the rotor with respect to the stator results in a static net force acting on the stator of the machine and additional spatial harmonics in the excitation spectrum. Whirling motion of the rotor creates an associated net whirling force and additional spatial and temporal harmonics in the excitation spectrum. Those excitation spectrums have been created and the vibration of the mechanical system as a result is analysed in each case. The authors have assessed the level of coupling between the mechanical and electrical systems required to successfully carryout these studies and a weak coupling approach is deemed suitable. The level and nature of machine housing vibration due to static and dynamic eccentricity is also detailed giving an overall assessment of the effect of eccentricity on NVH performance of a machine for an electrical vehicle application.
unbalanced magnetic pull, eccentricity, electrical machines, NVH, electric vehicles, drivetrain analysis, electromechanical simulation
17:55
conference time (CEST, Berlin)
Teaching Cyber-physical Systems co-simulation Using Jupyter-Lab
27/10/2021 17:55 conference time (CEST, Berlin)
Room: L
T. Roudier (E-Sim Solutions, CAN)
T. Roudier (E-Sim Solutions, CAN)
Latest technological advances in the design of cyber-physical systems increase the complexity of the interactions between the subsystems composing them. A telling example is the integration of network communication protocols subject to strict standards, including cyber-security considerations. They largely improve the accuracy on the interoperability between the subsystems. Nevertheless, they also make the system more complex to simulate. Designing and analyzing such multi-domains systems and their interactions requires the adoption of new concepts such as co-simulation, a concept which is not well mastered in most of cases. As a matter of fact, establishing co-simulation platforms is a challenging and complex task because of strong interoperability between the sub-systems composing the simulated environment, and more specifically with the integration of multiple formalisms together. Moreover, considering the diversity of physical domains involved and the constraints associated to their integration, the configuration and use of co-simulation platforms can be an obstacle course for people without expertise in IT and in systems interoperability. Obviously, many technical publications refer to the implementation of co-simulation platforms based on commercial software or on standards such as the Functional Mock Interface (FMI). The discussed solutions generally provide a powerful and dedicated environment for modeling and simulation of integrated systems on well known use cases. But none of these solutions really consider an environment where users might interact not only with simulation software, but also with the co-simulation process itself. Through this presentation we propose to discover the principles, the advantages, and drawbacks of co-simulation though an iterative and modular process supported by various co-simulation environments embedded in a portable platform and driven by a Jupyter-Lab web interface. Through an educational case study in robotics, a Lego Robot driven by a simulated controller through standard IoT messaging protocols, we propose a platform to learn how to design a complete co-simulation process by exploring among other topics: coupling methods, synchronisation algorithms and system partitioning. The proposed learning platform is also a powerful support to discuss constraints and issues imposed by the co-simulations helping users to identify when the concept should be implemented or not.
learning,co-simulation,python,cyber-physical systems,robotic
18:15
conference time (CEST, Berlin)
Multi-scale Drop Test Analysis of Printed Circuit Boards (PCB’s)
27/10/2021 18:15 conference time (CEST, Berlin)
Room: L
S. Medikonda, A. Srivastava, D. Lyu, W. Hu, A. Sengupta, R. Meena (Ansys Inc., USA)
S. Medikonda, A. Srivastava, D. Lyu, W. Hu, A. Sengupta, R. Meena (Ansys Inc., USA)
Solder Joints in PCB’s are typically observed to be the weakest links in the drop impact of most consumer electronics products. A drop-shock analysis and particularly the failure of solder joints involves the modeling of meso-scale solder joints and macro-scale chip packages, which is a typical multi-scale problem. Conventional finite element approaches using beam elements for the representation of the solders and the one-way sub-modeling technique cannot offer a high-fidelity solution in a reasonable amount of time. The two-scale co-simulation approach discussed in this study provides an efficient analysis tool to enrich Integrated Circuit (IC) packaging models with detailed solder joints so that complex failure modes of solder joints and corresponding structural response can be accurately captured. In this context, a detailed solder joint model of a consumer electronics board has been studied using a multi-scale approach in a drop test scenario. The local solder joint models are coupled to the large-scale global packaging model without the need for a conformal mesh at the coupling interface, this largely simplifies the workflow in both meshing, analysis and provides the flexibility to vary the characteristics of local solder models without the added cost of changing the global model. Under this proposed co-simulation framework, data exchange between the two explicit jobs (at different scales) occurs at the coupling interface synchronously using the Message Passing Interface (MPI). Additionally, this approach eliminates the constraint on time step variation imposed by a mesh-sensitive explicit analysis. The concurrent solder joint models with much smaller time-step sizes run separately from the global model, and communication happens at every global time step resulting in low overhead cost. Lastly, the multi-scale analysis has been carried out using the thick-shell/solid-shell PCB’s which are embedded with all the copper traces (as reinforcements) from an ECAD file and have been compared against a trace-mapped shell PCB model and a single scale high-fidelity model. The axial forces in the solder are one of the major post-processing quantities compared among all cases along with the maximum forces in the solders over the entire time history of the drop, this helps identify failure prone solders in the PCB. The multiscale results show a good correlation with the single scale high fidelity model thus validating this approach. A detailed HPC scalability study and the dependency on the no. of processors on the master and slave processes of a multi-scale analysis have also been discussed in detail.
solder ball, explicit analysis, co-simulation, multi-scale model
18:35
conference time (CEST, Berlin)
Electrical-Thermal-Stress Co-Simulation for 3D-IC Integrated with Package and PCB Board Designs
27/10/2021 18:35 conference time (CEST, Berlin)
Room: L
Z. Han, X. Ai, Z. Li, Y. Li (Cadence Design Systems, Inc., USA)
Z. Han, X. Ai, Z. Li, Y. Li (Cadence Design Systems, Inc., USA)
Three-dimensional integrated circuits (3D-IC) technology has been widely used in commercial products for lower power consumption, higher performance, and higher function density. The strong coupling among electrical, thermal and stress has been a great challenge in 3D-IC designs. In the paper, a fully integrated electrical-thermal-stress co-simulation flow is presented to address the challenges in 3D-IC designs. The complexity of vertical integration of many transistor planes and 3D structures of Through-Silicon Via (TSV) in 3D-IC designs makes the numerical simulation extremely challenging in the capacity and performance. In the presented simulation approach, some novel and innovative algorithms in finite element method (FEM) have been introduced to greatly reduce the numerical model size while preserving a proven accuracy in simulation results. With the technologies, this approach keeps the accuracy and flexibility of FEM to model complex structures while at the same time, employs the memory and computation efficiency for the large-scale design analysis. The coupling effect of a printed circuit board (PCB) and an IC package is of importance in 3D-IC designs. The seamlessly integrated method improves usability, capacity, and accuracy of the co-design and co-simulation from 3D-IC to package and board designs. Meanwhile the integrated environment is easily for user to enable the electrical, thermal and stress simulation which empowers simulation accuracy of FEM and design optimization. To verify the performance and accuracy of the new algorithms, a system on integrated chips (SOIC) design together with PCB and package designs are simulated and compared with the conventional FEM solver. The built-in model creator generates a simulation model with a few hundred of millions of nodes via a fully-automated process. The simulation is carried out on a cluster through a proprietary parallel solver. The thermal cycling stress analysis shows the detailed local distribution and estimates the safe life of the design. The simulation demonstrates that the great performance improvement in simulation time and memory usage can be achieved while the accuracy can be preserved. Meanwhile the dynamic thermal mitigation and thermal stress analyses are conducted to demonstrate the coupling effects crossing designs and domains.
Cadence, Celsius, FEM, Electrical, Thermal, Stress, Transient Analysis, Electrical-Thermal-Stress Co-Simulation, PCB, Package, Chip, 3D-IC.
×

[TITLE]

[LISTING

[ABSTRACT]

[DATE]

[ROOM]

[KEYWORDS]