Crashworthiness Challenges in Steel-to-Aluminum Front End Design

Author(s):  
Mohamed R. Baccouche ◽  
David A. Wagner ◽  
Hikmat F. Mahmood ◽  
Ismail O. Yaman

The search for weight reduction opportunities to improve corporate average fuel economy has led the auto industry to investigate light weight materials such as aluminum and magnesium. These materials can reduce vehicle weight while satisfying crash safety requirements of corporate, government, and independent insurance agencies. As a result, designs of several vehicles have been fully migrated from steel to aluminum while many other vehicles have opted to substitute lighter materials at the component and system levels. An investigation has been conducted on the front end principal crash energy absorbing rails to convert the original HSLA350 steel structural members into 5754NG aluminum. The investigation shows that while the substitution of aluminum at the right thickness can achieve lighter weight and higher specific energy, additional design parameters such as design load targets remain a major challenge. A comparison of steel versus aluminum mean crash loads, crash energy management, weight saved, specific energy, and design load target highlights some of these challenges. The results from an experimental investigation of stamped 5754NG aluminum sheet rails show the substitution of stamped 5754NG aluminum sheets for steel rails reduces the weight of each of the front rails by 3.3 (lb) and enhances the specific crash energy management efficiency by 38%. To solve the design load target challenge, the same investigation extends to higher strength 6xxx series extruded aluminum material using CAE modeling and demonstrates an increase in crash energy management efficiency of up to 80%.

Polymers ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 134
Author(s):  
Claudia Sergi ◽  
Fabrizio Sarasini ◽  
Jacopo Tirillò

Cork, a natural material from renewable resources, is currently attracting increasing interest in different industrial fields because of its cellular structure and the presence of the flexible suberin as its main chemical component. In an agglomerated form, it proved to be a compelling product not only as a thermal and acoustic insulator, but also as core material in sandwich structures and as a liner or padding in energy absorbing equipment. From this perspective, the assessment of its compressive response is fundamental to ensure the right out-of-plane stiffness required to a core material and the proper crashworthiness in the safety devices. Considering the complex nature of cork and the resulting peculiar compressive response, the present review article provides an overview of this paramount property, assessing the main parameters (anisotropy, temperature, strain rate, etc.) and the peculiar features (near-zero Poisson’s ratio and unique dimensional recovery) that characterize it in its natural state. Furthermore, considering its massive exploitation in the agglomerated form, the design parameters that allow its compressive behavior to be tailored and the operating parameters that can affect its crashworthiness were assessed, reporting some potential industrial applications.


Author(s):  
Michelle Priante ◽  
David Tyrell ◽  
Benjamin Perlman

In train collisions, multi-level rail passenger vehicles can deform in modes that are different from the behavior of single level cars. The deformation in single level cars usually occurs at the front end during a collision. In one particular incident, a cab car buckled laterally near the back end of the car. The buckling of the car caused both lateral and vertical accelerations, which led to unanticipated injuries to the occupants. A three-dimensional collision dynamics model of a multi-level passenger train has been developed to study the influence of multi-level design parameters and possible train configuration variations on the reactions of a multi-level car in a collision. This model can run multiple scenarios of a train collision. This paper investigates two hypotheses that could account for the unexpected mode of deformation. The first hypothesis emphasizes the non-symmetric resistance of a multi-level car to longitudinal loads. The structure is irregular since the stairwells, supports for tanks, and draglinks vary from side to side and end to end. Since one side is less strong, that side can crush more during a collision. The second hypothesis uses characteristics that are nearly symmetric on each side. Initial imperfections in train geometry induce eccentric loads on the vehicles. For both hypotheses, the deformation modes depend on the closing speed of the collision. When the characteristics are non-symmetric, and the load is applied in-line, two modes of deformation are seen. At low speeds, the couplers crush, and the cars saw-tooth buckle. At high speeds, the front end of the cab car crushes, and the cars remain in-line. If an offset load is applied, the back stairwell of the first coach car crushes unevenly, and the cars saw-tooth buckle. For the second hypothesis, the characteristics are symmetric. At low speeds, the couplers crush, and the cars remain in-line. At higher speeds, the front end crushes, and the cars remain in-line. If an offset load is applied to a car with symmetric characteristics, the cars will saw-tooth buckle.


2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Afshin Pedram Pourhashemi ◽  
S. M. Mehdi Ansarey Movahed ◽  
Masoud Shariat Panahi

In spite of occasional criticism they have attracted, hybrid vehicles (HVs) have been warmly welcomed by industry and academia alike. The key advantages of an HV, including fuel economy and environment friendliness, however, depend greatly on its energy management strategy and the way its design parameters are “tuned.” The optimal design and sizing of the HV remain a challenge for the engineering community, due to the variety of criteria and especially dynamic measures related to nature of its working conditions. This paper proposes an optimal design scheme that begins with presenting an energy management strategy based on minimum fuel consumption in finite driving cycle horizon. The strategy utilizes a dynamic programming approach and is consistent with charge sustenance. The sensitivity of the vehicle’s performance metrics to multiple design parameters is then studied using a design of experiments (DOE) methodology. The proposed scheme provides the designer with a reliable tool for investigating various design scenarios and achieving the optimal one.


2021 ◽  

Contents Structural components/Strukturbauteile Development of an energy-absorbing structural element made of polyamide integrated in the plastic front-end carrier of the new Mercedes S-Class ..... 1 Entwicklung eines energieabsorbierenden Strukturelements aus Polyamid integriert im Kunststoff-Frontendträger der neuen Mercedes S-Klasse ..... 5 BAGS: Highly-integrated front-end module carrier ..... 9 BAGS: Hochintegrierter Front End Modulträger ..... 19 Surfaces/Oberflächen Lightweight plastic construction with visible surface as examplified by the Volkswagen ID 3 tailgate ..... 29 Kunststoffleichtbau mit Sichtoberfläche am Beispiel der Heckklappe Volkswagen ID3 ..... 39 Breakthrough in producing soft and sustainable interior surfaces by injection moulding of TPE ..... 49 Simulation The all-new MAN high-roof cab – epoxy sandwich RTM – simulated using FEM and crashed under real conditions ..... 61 Epoxid-Sandwich-RTM – FEM gerechnet und real gecrasht ..... 75 Development and validation of a simulation methodology for the prediction of surface defects for plastic components with metallic effect pig...


Author(s):  
Karl Uebel ◽  
Henrique Raduenz ◽  
Petter Krus ◽  
Victor Juliano de Negri

This paper deals with design optimisation of hydraulic hybrid drivelines during early concept design phases. To set the design parameters of a hybrid driveline such as gear ratios, pump/motor displacements and size of energy storage, the energy management of the hybrid machine needs to be considered as well. This is problematic since a nested design and control optimisation normally requires substantial computer power and is time-consuming. Few previous studies have treated combined design and control optimisation of hydraulic hybrid vehicles using detailed, non-linear component driveline models. Furthermore, previously proposed design optimisation methods for on-road vehicles are not suitable for heavy off-road machines operating in short repetitive cycles with high transient power output. The paper demonstrates and compares different optimisation approaches for design and control optimisation combining deterministic dynamic programming and non-gradient based numerical optimisation. The results show that a simple rule-based energy management strategy can be sufficient to find the optimal hardware design even though non-optimal control laws are used.


Author(s):  
V. Nakhodov ◽  
O. Borychenko ◽  
A. Cherniavskyi

Statistics show that energy is one of the highest operating costs in a manufacturing enterprise. So, improving energy efficiency can lead to a significant increase in profits and reduce the impact of the enterprise on the environment. To increase the performance of energy efficiency activities, it is necessary to implement an energy management system. One of the components of this system is energy monitoring, which, in turn, is based on the periodic collection and analysis of data to assess the state of the monitoring objects in terms of energy efficiency. In this paper, the role and place of energy monitoring in the energy management system of an industrial enterprise are noted. The paper proposes the concept of creating energy monitoring system in industrial companies, which is based on the combination of a monitoring system based on specific energy consumption, and usage of group energy characteristics of production facilities. Implementing such energy monitoring systems will allow to conduct operational control of energy efficiency of production facilities by creating individual systems for monitoring energy efficiency, as well as successfully carry out such monitoring at the enterprise and its subdivisions over longer periods of time using specific energy consumption indicators. It also provides general guidelines for conducting energy monitoring. These guidelines were formed based on the results of studying various methods and scientific publications in the field of energy monitoring, as well as on the basis of practical experience in the development and implementation of energy management systems. Particular attention is paid to the issues of processing and analysis of information about the objects of energy monitoring of industrial enterprises. The practical application of the concept of creating energy monitoring systems envisages gradual improvement of the existing monitoring system based on the specific energy consumption, which will be further completely replaced with individual energy efficiency monitoring systems.


2018 ◽  
Author(s):  
Ethan Oblak ◽  
James Sulzer ◽  
Jarrod Lewis-Peacock

AbstractThe neural correlates of specific brain functions such as visual orientation tuning and individual finger movements can be revealed using multivoxel pattern analysis (MVPA) of fMRI data. Neurofeedback based on these distributed patterns of brain activity presents a unique ability for precise neuromodulation. Recent applications of this technique, known as decoded neurofeedback, have manipulated fear conditioning, visual perception, confidence judgements and facial preference. However, there has yet to be an empirical justification of the timing and data processing parameters of these experiments. Suboptimal parameter settings could impact the efficacy of neurofeedback learning and contribute to the ‘non-responder’ effect. The goal of this study was to investigate how design parameters of decoded neurofeedback experiments affect decoding accuracy and neurofeedback performance. Subjects participated in three fMRI sessions: two ‘finger localizer’ sessions to identify the fMRI patterns associated with each of the four fingers of the right hand, and one ‘finger finding’ neurofeedback session to assess neurofeedback performance. Using only the localizer data, we show that real-time decoding can be degraded by poor experiment timing or ROI selection. To set key parameters for the neurofeedback session, we used offline simulations of decoded neurofeedback using data from the localizer sessions to predict neurofeedback performance. We show that these predictions align with real neurofeedback performance at the group level and can also explain individual differences in neurofeedback success. Overall, this work demonstrates the usefulness of offline simulation to improve the success of real-time decoded neurofeedback experiments.


2019 ◽  
Vol 14 (10) ◽  
pp. 87 ◽  
Author(s):  
Arshia Taimouri ◽  
Korosh Emamisaleh ◽  
Davoud Mohammadi

Following the rapid development of the Internet, e-commerce websites are widely used today for various goals. An essential point in the prosperity of these websites is their level of usability. Accordingly, measuring this usability is indispensable for these websites to check whether they are moving in the right path. Thus, in this article, the usability scores of five well-known online food-ordering websites in Iran have been evaluated using a novel fuzzy Kano method with respect to design parameters. In addition to assessing usability scores, the design parameters of these websites have been classified and reviewed in a detailed manner in order to determine the design priorities of these websites as one of the main results of this study. Data were gathered using a questionnaire with 190 respondents. Results demonstrated that Snappfood is the best online food-ordering website in Iran. In addition, sorting restaurants based on customer satisfaction score, using high-quality images of foods along with the image zooming feature, and the existence of complete information about foods and restaurants are the most effective and important design parameters of these types of websites according to the findings of this study.


1999 ◽  
Author(s):  
Mohamed Ridha Baccouche ◽  
Hikmat F. Mahmood ◽  
Arkalgud K. Shivakumar ◽  
Saad A. Jawad

Abstract The quest for lighter crash energy absorbing automotive structures has increased the use, parallel with other materials, of the 5xxx sheet and 6xxx extruded aluminum structures. These aluminum structures, when properly designed and joined, are able to demonstrate a very high crash energy absorbing capability. This paper summarizes the CAE and development work performed in the design of the front end structure of a four door C-class space frame aluminum vehicle. Component and system CAE modeling of the front end were conducted under NCAP’s 35 mph full frontal impact using rigid body dynamic, nonlinear beam finite element and stability codes. Component loads versus crash distances and system deceleration versus time responses were computed. A 3D spring mass model was built for the front end structure using the rigid body and finite element code MADYMO. Spring characteristics for each component, derived from test data and component CAE models, were input into the MADYMO model. The deceleration-time response generated by the MADYMO model was used as input for the sled testing. The effects of four parameters were studied and discussed in this paper. These parameters are the steering column angle, IP, Pyro Buckle Pretensioner and airbag vent size. Dummy HIC; chest deceleration; neck shear, tension, compression, flexion and extension; femur load, pelvis acceleration and displacement; retractor load; shoulder belt load; lap belt load and other injury numbers, measured from sled test, are summarized and discussed in this paper.


Author(s):  
Sadjad Pirmohammad

This paper evaluates the crashworthiness performance of concentric structures with different numbers of tubes (i.e. one to five) and cross-sectional shapes (i.e. hexagon, octagon, decagon and circle) under the multiple loadings of θ = 0, 10, 20 and 30°. An experimentally validated finite element model generated in LS-DYNA is employed to calculate the crashworthiness parameters including the specific energy absorption, maximum crush force and crush force efficiency. A total of 20 concentric structures are analyzed to explore the effects of number of tubes and cross-sectional shapes on the crushing performance. A multi-criteria decision-making method known as TOPSIS is also used to compare and rank the concentric structures in terms of crushing performance. Based on the results, the hexagonal structure including two tubes and octagonal, decagonal and circular structures including three tubes demonstrate the best results among their corresponding cross-sectional shapes. These structures show 9, 39, 38 and 39% higher specific energy absorption compared to their corresponding single tubal cases, respectively. However, in comparison to single tubal cases, they generate 4, 57, 57 and 58% higher maximum crush force, respectively. As such, the values for the improvement of the crush force efficiency are 3, 26, 25 and 21%, respectively. Furthermore, the decagonal structure including three tubes provides the highest energy absorbing characteristics as compared with all the other structures studied in this research. Meanwhile, taking into account all the multiple loading conditions, this structure shows 50% higher specific energy absorption than the hexagonal structure including single tube (as the weakest structure).


Sign in / Sign up

Export Citation Format

Share Document