Pole Side Research Articles

Thermal–Electrical–Mechanical Coupled Finite Element Models for Battery Electric Vehicle

The safety of lithium-ion batteries is critical to the safety of battery electric vehicles (BEVs). The purpose of this work is to develop a method to predict battery thermal runaway in full electric vehicle crash simulation. The thermal–electrical–mechanical-coupled finite element analysis is used to model an individual lithium-ion battery cell, a battery module, a battery pack, and a battery electric vehicle with 24 battery modules in a live circuit connection. The lithium-ion battery is modeled using a representative approach, with each internal battery component individually modeled to represent its geometric shape and realistic thermal, mechanical, and electrical properties. A resistance heating solver and Randles circuit model built with a generalized voltage source are used to simulate the electrical behavior of the battery. The thermal simulation of the battery considers the heat capacity and thermal conductivity of different cell components, as well as heat conduction, radiation, and convection at their interfaces. The mechanical property of battery cell and battery module models is validated using spherical punch tests. The electrical property of the battery cell and battery module models is verified against CircuitLab simulation in an external short-circuit test. The simulation results for the battery module’s internal resistance are consistent with both experimental data and literature values. The multi-physics coupling phenomenon is demonstrated with a cylindrical compression simulation on the battery module. The multi-physics BEV model with 24 live battery modules is used to simulate the external short-circuit test and the side pole impact test. The simulation run time is less than 24 h. The results demonstrated the feasibility of using a representative battery model and multi-physics analysis to predict battery thermal runaway in full electric vehicle crash analysis.

Oblique pole-side crash assessment using the six-year-old HBM PIPER

Side impact crashes are one of the most dangerous impact scenarios that a child can suffer. Studies by the National Highway Traffic Safety Administration (NHTSA) have shown that the head and Thorax regions are affected severely. The objective of this work is to perform a numerical evaluation of the oblique pole-side test considering the FMVSS 214-P standard to estimate the Head, Neck, and Thorax injuries for a six-year-old child positioned in the rear seat without any Child Restraint System, two configurations were performed for the oblique pole-side impact: a nearside and a far-side positioning configuration. A six-year-old Human Body Model (HBM) denominated Scalable PIPER Child Model, and the Ford Explorer 2003 were used to perform the test in the LS DYNA® software to assess the biomechanics involved in the crash scenarios. The approach considered a comparative case study with the baseline of the six-year-old child PIPER model to ensure that the positioning adjustment has not affected the mesh quality and interior components for the PIPER child model. The outcomes obtained in case 1 show that the modified PIPER child model has slight outcomes at the shoulder and pelvis zone due to the differences in the body positioning and not by the mesh or the interior interaction between the components. The outcomes obtained in case 2 reflect that the nearside setup obtained the higher measurements for the child occupant. The Ac3ms for Head at nearside test to overcome the Side Criteria established by the Assessment Protocol Child Occupant Protection by Euro NCAP, the kinematics behavior demonstrates the importance of researching children in side crashes to enhance child security, especially in the oblique pole side impact.

Bearing Capacity Analysis of Floating Foundation Model in Homogeneous Very Soft Clay

Abstract This study focused on the effect of trapped water on the bearing capacity of PVC pipe pile foundations. This research is divided into two models. The first model (pressure cap pipe pole) and the second model (open press pipe pole) each consist of four variations of PVC pipe diameters of 5.08 cm, 6.35 cm, 7.62 cm, and 10.16 cm (standard size PVC pipe diameter) with the same length of 30 cm. In the first type, all pipes are tightly closed at their upper ends. In the second type, all upper-end caps are given two holes, each with a diameter of 0.5 cm. Each pipe pile is alternately piled into soft soil with a moisture content of 98.8% is in a glass box measuring 120 cm x 20 cm x 60 cm. The test results of the load against decrease were analyzed using the Mazurkiwicks interpretation method. The bearing capacity of the end of the pole (Qp) along with the air trapped in the pipe pile (QA) can increase the carrying capacity of important poles compared to the carrying capacity of the pole side (Qs). PVC pipe poles belong to the floating pile foundation group due to the influence of air trapped inside the pile.

Application of Macro Element Method (MEM) for faster automotive crash safety design during concept stage

The non-linear nature of vehicle crash safety simulations using the Finite Element Method (FEM) usually requires a significant investment in computational time and resources, in addition to the requirement of full CAD (Computer Aided Design) data availability, which is challenging to obtain during the concept stage. The current work explores the usage of Macro Element Method (MEM) based on simplified Super Beam Element (SBE), for which the shape functions are developed based on experimental observations rather than algebraic equations. MEM crash analysis run time doesn’t exceed several seconds and is one of the underutilised analytical models which can be used to quickly explore new design directions during the early concept stage of the vehicle and has higher potential to speed up the product development process. In this paper, initially, a calibration study was done to validate the MEM at a component level to compare the results with FEM and experimental values. FEM and MEM simulation models were developed and evaluated for a metallic thin-walled square frusta with varying semi-apical angles subjected to axial compression. The results were compared, and it was found that MEM results show more than 97% correlation compared to FEM and experimental results. Subsequently, a design modification was introduced in the component and the results show close degree of correlation between MEM and FEM. Similar process was followed for full vehicle level simulations, such as full width frontal crash, side pole crash analyses to understand the robustness of the method in applying it to product development environment.

Design and analysis of underwater power generation characteristics of deflected double-stator switched reluctance generator

The Deflectable double-stator Switched Reluctance Generator (DSRG) has the advantages of simple structure, small volume and multi-dimensional operation. The DSRG and propeller are combined into the application of underwater power generation. With the help of the deflect ability of the generator, the efficiency is improved. Due to the uncertainty of ocean current direction and the structure of switched reluctance generator, the torque ripple is one of the important factors damaging the underwater generator. In order to effectively suppress the influence of torque ripple caused by generator operation, a method of adding pole shoes on the pole side of outer stator is proposed, so as to reduce the torque ripple. The propulsion structure running at different deflection angles is simulated. The torque and speed obtained before and after pole shoe optimization are input into the propeller model. The pressure and speed characteristics of the corresponding blade structure are simulated to verify the effect of optimization and the effectiveness of the power generation system.

Parametric Analysis of a Divided Rocker for Battery Electric Vehicles

The driving range of an electric vehicle can be increased through an efficient integration of the large battery within the vehicle structure. In this regard, a divided rocker concept from an existing study is investigated, in which the vehicle rocker is divided into two parts by means of a division plane. One part of the rocker remains vehicle sided and enables the attachment of the surrounding vehicle structures, while the other part is functionally integrated into the side frame of the battery housing. In the scope of this paper, several division plane concepts for such a divided rocker are created and analyzed. The crash performance of the modelled division plane concepts is studied on a component level using the side pole crash test as a load case. For the different division planes, a parametric analysis is performed by varying the number of chambers in the rocker profile, the chamber width, mass distribution, individual section thicknesses, the height of the division planes, and the air gap between the vertical surfaces of the division planes. Several crash performance criteria, such as structural deformation, force, and energy absorption, are examined. Among the studied parameters, the number of chambers and mass distribution have notable influences, while individual section thicknesses and the height of the division planes do not have a significant influence on the crash performance. Lastly, stiffer chambers in the battery-sided rocker created by decreasing the chamber width have the strongest effect on crash performance.

Staggered layout of battery cells for mitigating damage in side pole collisions of electric vehicles

Staggered layout of battery cells for mitigating damage in side pole collisions of electric vehicles

Numerical investigation of crash behavior of vehicle side door beams under high-speed pole side impacts

In side vehicle accidents, there is a very short distance between the impactor and the passenger. In such accidents, car manufacturers place impact energy absorber beams inside the door so that the passengers do not suffer from loss of life or major damage. In this study, the crashworthiness performances of impact energy absorber beams were investigated. Comparisons were made by changing the beams’ angles, materials, thickness, and cross-sections. Among the materials used (Aluminum 6061-T6 and A36 steel), Aluminum 6061T6 material stood out with its high Specific Energy Absorption (SEA) value, low reaction force, and low permanent deformation performance. The best Velocity Absorption Time (VAT) value was obtained in the combination where the angle between the two beams defined by A36 steel was 25°. It has been stated that the hexagonal cross-section door beam used is superior to the circular beam and is open to improvement.

Analysis of Crashworthiness of Bishoftu Pickup Vehicle Structure during Side Pole Crash

Now a day’s, vehicle accident is becoming a critical issue all over the world, especially in Ethiopia. These vehicles have not been checked for any crash safety test specifications and are not evaluated for crashworthiness. So, it is now time to consider the safety features of Bishoftu pickup vehicles (BPV) to reduce the grave consequences for their users. This paper aimed to improve the crashworthiness of the existing Bishoftu pickup vehicle through remodeling. The structural response to a frontal collision with an existing BPV is analyzed. Based on the results obtained from the existing model, modifications are made by means of energy-absorbing components, a stable frame structure, and better crash performance. For doing the analysis software like CATIA is used for 3D modeling, and LS-DYNA is used for FEM analysis. The results show that by applying the modification, 39 kN (7.82%) of impact force is reduced and 5 kJ (3.52%) of additional energy is absorbed during the frontal collision. Finally, it can be concluded that with the modified model, the safety and crashworthiness of the BPV were greatly improved without affecting the appearance and weight of the existing one.

Safety and stability analysis of variable cross-section disc-buckle type steel pipe high support system

In order to solve the problems of poor safety and difficult determination of construction scheme in the construction process of variable cross-section disc-buckle type steel pipe high support system, based on the stress state of the normal working of the disc-buckle type formwork support, the stability bearing capacity of vertical poles under three working conditions of central pole, side pole and corner pole were experimentally carried out, and the correctness were verified by comparing with the results of the experiment and finite element analysis. Based on the verified finite element model and the characteristics of semi-rigid connection joints, the first-order buckling mode and nonlinear buckling analysis of the stability bearing capacity of the variable cross-section disc-buckle type steel pipe high support system were carried out in the construction period with special structure in practical engineering, the stability bearing capacity and deformation law of the variable cross-section disc-buckle type steel pipe high support system in the construction process were mastered. Through parametric analysis of the influencing factors such as the joint bending stiffness, the setting parameters and the initial imperfections, the influence law of the relevant parameters on the overall stability of the variable cross-section disc-buckle type steel pipe high support system was grasped. The results showed that the corner poles at the higher variable section and the lower variable section of the weak stiffness direction support system were prone to instability and failure. The overall stability bearing capacity was mainly affected by the lift height. The vertical diagonal bracing plays an important role in improving the overall stability, the larger the lift height was, the more obvious the improvement was. The overall stability bearing capacity decreases with increasing top extension length, and the top extension length should be controlled within 0.45 m. When the extension length of the top was greater than 0.45 m, the initial imperfection cannot control the overall stability bearing capacity, and the overall structural stability bearing capacity was determined by the buckling behavior of the top vertical pole. When the joint bending stiffness was greater than 2.0 K, the stability bearing capacity does not change. The higher the support system was, the smaller the influence of joint bending stiffness on the overall stability was.

Study of the Effect of the Geometry of the Inner Pole Arm of a Bipolar Lens

Several innovative designs were designed for magnetic lenses, a bipolar lens with innovative and different geometric shapes, where the outer Inner pole side of the iron shroud, which is symbolized by the symbol (L), was changed. 2,4,6 A/mm2) and after it was designed, the engineering parameters were studied in terms of magnetic properties, i.e., calculating the magnetic flux density with different current densities, and then studying the optical properties in terms of spherical aberration as well as chromatic aberration. Which made slight changes to the magnetic and optical properties of the bipolar lens and led to an improvement in the performance of the lens because the resolving power increased its amount when the change was made, as well as the aberration where both spherical aberration and chromatic aberration decreased.

Reducing the failures with adding glass insulators to composite insulators of 400 kV transmission line at high altitude

Using composite insulators instead of glass insulators in high voltage transmission lines has become common with rapid developments in material technology. This study examined the 270 km long İspir-Bağıştaş high voltage line with a 400 kV composite insulator, which was commissioned in 2016. The altitude along the transmission line route varies between 860 and 2800 meters. After the line was commissioned, too many phase-earth failures were experienced. To reduce failures, the Turkish Electricity Transmission Corporation (TEİAŞ) operator added glass insulators to the existing composite insulators. It was observed that the number of failures decreased significantly after the addition. That study aims to find the most suitable location and the number of glass insulators. Since the design of the insulation system is crucial for network reliability and sustainability, it has become a necessity today to carry out analysis before the design stage. In this context, the pole-insulator systems used in the transmission lines were modelled in the Ansys Electronic Suite finite element analysis program. The influence of the conditions applied in the field was examined. Accordingly, when one, two and three glass insulators are added to the conductor side, the maximum electric field distributions on the composite insulator surface decrease by 19%, 35% and 45%, respectively. In the case of adding glass insulators to the pole side, there is no significant change in the electric field distribution formed on the composite insulator surface. In addition, when adding one, two and three glass insulators, the minimum arc distances increase by approximately 12%, 19% and 21%, respectively. Accordingly, adding three glass insulators to the composite insulator would be appropriate to reduce the failures without changing the composite insulators. Although the electric field decreases up to 45% when glass insulators are added to the conductor side, it would be convenient to add them to the pole side for easy application on the field. Due to the arc distances, it is not recommended that the number of glass insulators is added by more than three for the examined system. The number of faults in the line decreased by 82% in the first twelve months following the addition of the glass insulator to the pole side, which shows the benefit of the application. That application is essential in terms of reducing the problems in live lines without changing existing insulators.

Analysis of Three-Wheeler Vehicle Structure at the Event of Side Pole Crash

This work reports on the simulation of three-wheel vehicles in the event of a side pole crash. In this study, the dynamic characteristics of the three-wheeler vehicle during pole collision were studied using finite elements. The TWV model used here was created using CATIA v5 and simulated using LS-DYNA which is widely used by the automotive industry to analyze vehicle design and predict a car’s behavior in a collision. Moreover, in this study, the finite element model of the side hybrid 5th percentile male dummy was developed for studying the driver and occupant responses in crash events of side pole. Based on the analysis results obtained from the existing model of TWV, modifications were made on the side structure by means of adding energy-absorbing components. Then, the modified TWV was analyzed under the same condition as the existing one. The result of the simulations shows that with the modification, 80 mm more living space, 630 N reduction of impact force, and 0.8 kJ of additional absorbed energy were obtained. So with the modified model, the safety and crashworthiness of the TWV were greatly improved during side collision without affecting the appearance and weight of the existing models.

An integrated energy absorbing module for battery protection of electric vehicle under lateral pole impact

Nowadays, the importance of energy conservation and environmental sustainability issues has led to developments of environmentally friendly products like electric vehicles (EVs). The EVs are not already as widespread as internal combustion engine vehicles (ICEVs) and also the complicated inherent crash behaviour put their crashworthiness at the first development steps. However, besides the battery safety, other major issues such as corresponding vehicle crashworthiness as a consequence of engine and sub-related components elimination and also battery packaging should be addressed. Although before reaching a more specific crash limits for EVs safety evaluation test cases, one could use the ICEV’s conventional crash scenarios for the structural crashworthiness evaluations. In this article, the side pole impact as the severe load case according to ENCAP was introduced and protection of the battery pack is improved by implementing a novel energy absorber element into the body sill side. The analyses have performed based on validated computational simulations. The finite element model of the structure is prepared by ANSA and the simulations carried out via ABAQUS and the non-linear explicit finite element software of PAM-CARSH. The various assessment criteria such as pole intrusion, internal energy, section loads before and after the conversion are analysed in order to find an optimum configuration of the structure for battery protection. Obtained results show a significant enhancement in vehicle crashworthiness performance.

Avoiding structural redundancies between the vehicle body and the battery housing based on a functional integration approach

In this paper, the approach for a functionally integrated battery housing is presented, to avoid structural redundancies towards the vehicle body. The goal is to reduce the overall structural weight while simultaneously increasing the package space for battery modules. The typically existing boundary conditions for the battery system are taken into account. Especially, the detachability of the battery as a closed unit is in focus, to ensure the leak tightness of this system and to enable replacement. Based on the available space in a research vehicle, such a functionally integrated concept is developed. In particular, the vehicle floor and the vehicle rocker are identified as suitable components for integration. The verification of the concept with regard to the crash performance is carried out on component and on full vehicle level. On both levels, the side pole impact is used as load case and the deformation behavior is investigated.

Crashworthiness among side pole testing

This research presents results from measurement data analysis of 47 oblique side impact pole crash tests conducted for the New Car Assessment Program (NCAP). Integrating measured acceleration data allowed to calculate changes of velocity and other key parameter like coefficient of restitution of the impacts. An objective of this work was, to obtain parameters for the side crash, which can be useful for vehicular accident reconstruction. Despite of identical test velocity, we can observe a wide range of kinetic energy induced due to the to some extent tremendously differing masses of the vehicles. In addition, the part of this energy, which is dissipated into deformation energy, differs enormously. In some cases, the kinetic energy after impact is unexpected high, which in this case is equal to a comparatively large change of velocity (Δv). Analysing the dummy measurements of the considered side pole tests, we cannot observe a relationship between velocity change of the vehicle and load of the dummy. Resultant restrictions for the use of delta-V as crash severity metric or predictor for the risk of injury are discussed.

Multi-objective optimization design of B-pillar and rocker sub-systems of battery electric vehicle

B-pillar and rocker are the key force transmission sub-systems of the side impact of battery electric vehicle (BEV), and scholars have studied the side crashworthiness of these sub-systems and vehicle body a lot. However, these works are insufficient on the analysis of benchmarking vehicle models, the simulation and experiment of the B-pillar and rocker sub-systems, and the optimization of these sub-systems. To make up these shortcomings, this work aims to design the B-pillar and the rocker and improve the side crashworthiness of BEV. It presents a systematic method on the side crashworthiness of BEV. The dynamic bending performance of the B-pillar and the rocker are studied in simulation analyses and experiments. The materials, structures, and crashworthiness of these two sub-systems of eleven benchmark models are studied. Minimizing structural mass and cost as well as maximizing mean crushing force are performed based on multi-objective artificial tree algorithm to optimize the B-pillar and the rocker. The optimized sub-systems are applied to the body of a BEV. As a result, the performance of the B-pillar and the rocker is significantly improved, and their optimal solution templates are provided. The performance of the BEV is also improved under the advanced European mobile deformable barrier side impact and the oblique pole side impact. Some interesting conclusions for BEV are presented. In summary, this work has obvious reference value for automotive engineers and scholars to further study the crashworthiness and lightweight of BEV.

Design optimization of a novel negative Poisson's ratio non-module battery pack system considering crashworthiness and heat dissipation

Considering volumetric energy density (VED), crashworthiness and heat dissipation, this paper explores a novel battery pack system containing a non-module battery pack (cells to pack, CTP) and two negative Poisson's ratio (NPR) tubular structures. The CTP is designed to maximize the battery pack's VED by removing the module components and assembling the large-size battery cells into the pack. On this basis, the NPR tubular structures consisting of NPR anti-collision block and NPR radiator are installed on both sides of the CTP to meet the crashworthiness and heat dissipation requirements. In detail, the NPR anti-collision block is employed to protect the NPR-CTP system in side pole impact accident, and the NPR radiator filled with cooling water can dissipate heat with outside air. Furthermore, a many-objective optimization methodology integrating an improved radial basis function (PSO-RBF) neural network model and the third-generation nondominant sorting genetic algorithm (NSGA-III) is used to search the optimized NPR-CTP system. The results show that the initial NPR-CTP system has better crashworthiness and heat dissipation than the other CTP systems, and the comprehensive performance of the optimized NPR-CTP system has been effectively strengthened.

A component development method for vehicle body structure based on limited vehicle data

Due to the reduction of vehicle development time and cost constraints, increasing volumes of vehicle development work are being transferred from automotive manufacturers to suppliers. In the area of vehicle structure development, one of the major challenges for suppliers is to deliver a good structural solution in a short time with very limited vehicle data. For those crash-relevant components or modules, such as the A- and B-pillar and the door module, considerable inaccuracies can be expected in the results when using partial vehicle data, as opposed to complete data, with the traditional component validation methods. In this work, a new component development method has been developed, and its implementable crash test bench for small vehicles has been virtually realised. This method focuses on the side impact tests at this phase, such as side impact with a mobile deformable barrier and a side pole impact. Reducing the number of required surrounding components and finding proper boundary conditions that can be implemented in the real test bench are the principle objectives of this work. The results of the crash simulations show a good correlation between the component sub-model and the full vehicle (FV) model using this method.

기둥측면충돌시험을 고려한 전기자동차 차체 및 배터리 팩 통합 구조물의 비선형동적응답 구조최적설계

A nonlinear, dynamic response structural optimization is carried out for a structure that integrates the body-in-white and battery pack of an electric vehicle. The loading conditions are made from a side pole impact test. The objective function is the mass, while the intrusion of the battery pack is defined as a constraint to prevent fires or explosions involving the battery pack during a car accident. An optimization method that uses the equivalent static loads method(ESLM) is proposed. An electrical vehicle(EV) model is generated from an existing crash simulation vehicle model. The proposed method was found to be an effective structural design method for electric vehicles.