Automotive Body Research Articles

Research on detection and classification of automotive body surface defects based on image processing and machine learning

Abstract The high noise in the automotive body surface image makes it difficult to extract defects. Moreover, a single feature cannot describe the complex automotive body surface defects leading to low classification accuracy. This paper proposes a highly robust method for classifying body surface defects. Firstly, an edge detection method that integrates the wavelet transform and the mathematical morphology is applied to detect defects. Subsequently, the geometric features of detected defects are combined with scale-invariant feature transform features to be the classification basis. Finally, the classification accomplishes through a support vector machine(SVM) with the parameters optimized via the grey wolf optimizer-SVM. Experimental results show the proposed classification method based on feature fusion achieves an average of 93% accuracy in automotive body surface defects classification and exhibits a 100% classification accuracy for pseudo-defects, which demonstrates the fusion of the wavelet transform and the mathematical morphology for automotive body surface defects detection can effectively reduce the impact of image noise for ensuring the extracted edges are intact.

Effect of paint baking treatment on microstructure and properties of 6082 aluminum alloy CMT welded joints filled with AlSi10Cu2Mg0.7Zn1 wire

Aluminium alloy 6082-T6 is known for its high strength and cost effectiveness, making it a popular choice for thin sheet structures such as automotive body panels. However, the welding-induced softening of the heat affected zone (HAZ) and the insufficient strength of the filler metal are the primary factors limiting its broader application. In this study, the lower heat input cold metal transfer welding method is employed, utilizing heat-treatable reinforced AlSi10Cu2Mg0.7Zn1 wire to weld 6082-T6 plates. Additionally, the impact of the baking paint process within the automotive manufacturing workflow on the evolution of microstructural characteristics of the HAZ and Weld Zone (WZ), as well as the mechanical properties of the joints, is investigated in detail. The findings indicate that the AlSi10Cu2Mg0.7Zn1 filled WZ contains a small quantity of θ, Q, and β phases, alongside a significant amount of reticulated eutectic Si distributed among the Al dendrites. Notably, the strength of the WZ is enhanced compared to that of conventional Al–Si and Al–Mg wires. During the baking process, the WZ exhibits the precipitation of a small amount of fine β’’ and β′ precipitates, which elevates the tensile strength of the WZ to 272 MPa and the yield strength to 179 MPa. Furthermore, the baking treatment promotes the further growth of β′ in the HAZ of the joints, while fine β’’ phases are reprecipitated within the Al matrix. The combined influence of these two precipitated phases results in an increase in the tensile strength of the HAZ by 29 MPa.

Optimizing drying time of lacquer-based MTCS-modified SiO2-TiO2 coatings for enhanced mechanical durability, superhydrophobicity and photocatalytic activity

This research successfully improved the mechanical durability of a superhydrophobic coating on wet lacquer. Methyltrichlorosilane (MTCS) modified SiO2-TiO2 nanoparticles (NPs) were applied to a wet lacquer layer with various drying times using a simple spraying technique. The optimal coating exhibited superhydrophobicity with a water contact angle of 157° and a sliding angle of 2°. Additionally, the superhydrophobic surface could withstand over 100,000 water drops, 200 g of sand, and 40 tape-peeling repetitions, indicating high mechanical stability. Moreover, the superhydrophobic surface demonstrated photocatalytic activity by degrading methylene blue (MB) solution. The coating showed excellent adaptability to different substrates, including automotive body panels, with self-cleaning properties. This simple and effective strategy has potential for large-scale fabrication for practical applications in various industrial fields.

Design optimization of automotive carbon fiber composite material floor laminate based on PSO-BFO algorithm

In response to the current challenges of low precision and efficiency in the optimization of composite material layups, the insufficient lightweight of automotive body floors, and the high cost of carbon fiber composites, this study introduces an optimized design method for carbon fiber composite flooring layups. Based on implicit parametric technology, a hybrid PSO-BFO (Particle Swarm Optimization-Bacterial Foraging Optimization) algorithm is employed. This approach achieves an integrated optimization of materials, processes, and structures, thereby balancing and reducing costs. The SFE-CONCEPT is utilized to establish an implicit parameterization model for the body floor, which is validated through experiments and finite element simulation analysis. Concept design and modeling of the carbon fiber composite material floor laminate are performed. Continuous variable optimization is employed to determine the thickness, tile shape, and number of layers for the front, middle, and rear floors. A continuous variable discretization rounding strategy is used to obtain the discrete layer numbers for each laminate orientation of the composite material floor. The continuous fiber lamination strategy is applied to create different shared lamination regions. The PSO-BFO hybrid optimization method is proposed to optimize the lamination sequence as a multi-objective optimization, addressing the challenges of discrete lamination sequence, explosive combinations, and multiple variables in the optimization design of carbon fiber composite material floor laminates. The optimization results demonstrate improvements of 34.4% in floor quality M, 6.0% in static bending stiffness BS, and 5.3% in lightweight coefficient QLX using the proposed PSO-BFO method. PSO-BFO and PSO-GA (Particle Swarm Optimization-Genetic Algorithm) methods are more capable of obtaining global optimal solutions for complex optimization problems than single optimization algorithms. Still, the results obtained by the PSO-BFO method are more balanced.

Carbon Micron-size Content Dependency in Epoxy/Carbon Composite Coated onto SPCC Plate for Automotive Bodies Protection

Conventional epoxy coating for surface metal corrosion protection reported many unsolved technical problems. Adding filler in the epoxy could enhance the promising properties of the composite coating. Our work describes in detail the synthesizing and characterizing epoxy/carbon composite coating. Epoxy was mixed with thinner high gloss (HG) and hardener and stirred using a stirrer apparatus. After blending, various carbons were added (1 wt. %, 3 wt. %, and 5 wt. %) and then appropriately stirred. The different mixture composite was coated onto the steel plate cold rolled coiled (SPCC) plate using high-volume low-pressure (HVLP) in two passes. Various characterizations were performed, including crystallographic orientation, Infra-Red (IR)-spectra, surface morphology, thickness, hydrophobicity, hardness, and corrosion using X-ray diffraction (XRD), Fourier transform infrared (FTIR), Scanning electron microscopy (SEM), portable dry film coating thickness (DFT), digital camera, Vickers microhardness tester, and Potentiostat, respectively. More carbon micron-sized content led to elevate the peak intensity, surface bumpiness, and hydrophobicity. The uppermost external bumpiness and hydrophobicity values are 23.51 µm and 101◦. Hardness depends on carbon content and more carbon leads to an increase in the hardness of the composited coating. The highest average Vickers hardness value is 28.24 HV. The coating thickness influenced the corrosion rate, more coating thickness promoted lesser corrosion rate. The highest coating thickness (60.8 µm) promoted a corrosion rate of around 5.65×10−4 mmpy.

Evaluating Sustainable Materials for Automotive Applications Through Comprehensive MCDM Analysis Using CODAS, COPRAS, VIKOR, and ENTROPY

The automotive industry faces increasing pressure to incorporate sustainable materials in vehicle manufacturing to meet environmental, economic, and performance requirements. This research develops a comprehensive Multi-Criteria Decision-Making (MCDM) framework to evaluate and select sustainable materials for automotive body and instrument panels. The study integrates CODAS, COPRAS, VIKOR, and ENTROPY methods to systematically assess various material alternatives. By considering multiple criteria, including cost, environmental impact, and mechanical properties, the proposed framework provides a holistic evaluation to identify the most suitable materials. The findings contribute to advancing sustainable practices in the automotive industry, offering manufacturers a robust tool for informed decision-making. This approach supports the industry's transition towards environmentally responsible and efficient vehicle production, ensuring that the selected materials meet the stringent demands of modern automotive design.

Expanding Lightweight Design Potential by Hybrid Joining of Aluminum Sheets with Aluminum Casting Through Compound Sand Casting and Induction Heating

Combining light metals like aluminum to produce lightweight structures offers a high weight‐saving and contributes to a circular economy in automotive car body construction. Compound casting is a promising process for producing car body parts. Difficulties arise in creating metallic continuity between insert and casting. Insert coatings are used to remove the oxide layer and thereby improve the wettability of the melt. This study uses a hybrid joining method to improve the metallic bond between insert and casting. Induction heating differently influences the strength properties of age‐ and nonage‐hardenable inserts. Compression shear tests characterize the metallic bond strength. Microscopic images show the influence of the process variables on the compound quality. Reproducible sound metallic bonding with low scattering is achieved by enhancing the compound casting process through induction and no insert coating. Cast wall thicknesses down to 4 mm contribute to further lightweight potential as they have the same strength level as the reference sample. A decisive factor is the insert temperature in the compound zone. Thereby, insert preheating conditions play a crucial role. Additional heat treatment of hardenable compounds leads to a further increase in metallic bond strength.

Ion-selectivity of galvanic corrosion products formed in multi-material gaps under atmospheric corrosion conditions with anti-freezing salts

Several multi-materials, which are joints of high-strength steels and lightweight materials such as aluminum alloy and carbon fiber reinforced thermoplastic, were subjected to the cyclic corrosion test for simulating atmospheric corrosion of automotive bodies and outdoor exposure tests. The ion-selectivity of the corrosion products formed in the multi-material gaps was examined by a membrane potential measurement. The corrosion products of all examined joints showed anion-selectivity rather than cation-selectivity. Corrosion products formed in joint gaps were less effective in preventing the progression of galvanic corrosion, suggesting that sufficient atmospheric corrosion protection is required for the use of multi-materials.

Pengembangan Modul Pembelajaran Mata Pelajaran Pengecatan Bodi Pada SMK Program Keahlian Teknik Bodi Otomotif

This research is a development research (research and development) with the development of learning media in the form of Automotive Body Engineering modules in Class XI Body Painting Subjects at SMK Kristen 5 Klaten using the Four-D method by Thiagarajan and Semmel which has been modified. The stages used in the module development process are the defining stage (define), the design stage (design), the development stage (develop) and the dissemination stage (disseminate). Collecting feasibility data using questionnaires and observations. This study involved material experts, media experts, subject teachers and students to obtain module feasibility assessments and responses. The data analysis technique used was quantitative descriptive analysis.The results showed that: 1) produce an Automotive Body Engineering learning module; 2) the Automotive Body Engineering learning module at SMK Kristen 5 Klaten is feasible to use based on the results of material expert validation with a percentage of 76.08% and the results of validation by media experts with a percentage of 73.80% with a decent category; The results of the assessment of the feasibility level of the Automotive Body Engineering learning module at SMK Kristen 5 Klaten by the subject teacher with a percentage of 88.23% with a decent category; 4) The results of the assessment response from class XI students were 94.14% with a very feasible category.

Investigation of Temperature Impact on Friction Conditions in Running Production of Automotive Body Components

During the running production of automotive body components drifts in the process window is seen causing problems with non-conforming parts. Up until now, these drifts have been counter-acted based on the knowledge and experience of the press line operators. This experience-based process control will however become more troublesome in the future as recycled material grades will undoubtedly present larger in-coil variations in material parameters and effect also the friction conditions from component to component.The following study will present two cases from production of the Volvo XC60. For the two cases, the initial simulations made for the components showed a safe part, but during running production failure occurred suspected to be due to temperature effects in the tribology system. The study will furthermore present updated simulations considering developing thermal effects to replicate the failures, as well as present both standard and thermal simulations of the adjustments made in production.

Creating a Virtual Shadow of the Manufacturing of Automotive Components

Within the automotive industry, there is an increasing demand for a paradigm shift in terms of which materials are used for the manufacturing of the automotive body. Global climate goals are forcing a rapid adaption of new, advanced, sustainable material grades such as the fossil free steels and materials containing higher scrap content. With the introduction of these new and untested materials, methods for accounting for variation in material properties are needed directly in the press lines.The following study will focus on creating an initial virtual shadow of the manufacturing of a Volvo XC90 inner door panel through the application of Artificial Neural Networks (ANN). The virtual shadow differs from the concept of the digital twin by only being a virtual representation of the production line, with training data generated exclusively by numerical simulations, and having no automated communication with the physical press line control system. The virtual shadow can be used as an assistance to the press line operators to see how different press line settings and material parameter variations will impact the quality of the stamped component. The study aims to validate the virtual shadow through accurate predictions of the material draw-in measured in the physical press line.

Remanufacturing Assessment of Machine Tools under a Circular Economy Perspective: A Resource Conservation Initiative

Machine tools are recognized as goods-generating equipment that constitute the realm of manufacturing facilities, providing the means of production for the generation of consumer products. This work explores the possibility of implementing sustainability concepts, employing criteria from a circular economy in the design and manufacturing of new equipment, using existing structural elements as the basis for the development of these machines. Stamping presses for automotive body panels were considered as the focus of this study. A quantitative evaluation of the possibilities for reusing existing components was developed using an algebraic tool, through the creation of algorithms that facilitate the comparative analysis of production costs and delivery lead times. Additionally, a case study was conducted to assess the capability of these algorithms to provide results, presented as comparative indicators that should be taken into consideration and may assist in the decision-making process regarding the implementation or not of the possibilities presented by the study. The simulation performed proved to be proficient, providing data that can guide decision making regarding the reuse of the chosen structural elements, based on their soundness verified through inspections conducted by the machine designers.

Method of Increasing the Fracture Toughness of Unsaturated Polyester with the Addition of Vinyl Ester as a Material for Automotive Body

Unsaturated polyester is the polymer material most widely used for matrix composites in the field of construction engineering, including for ships, automotive components and other engineering fields. The weakness of this polymer is that it is brittle and brittle and is unable to withstand cracking loads due to having cross-linked molecules that easily link together. The study to improve it was mixing with vinyl ester which succeeded in making the polyester crack resistant which was tested using a CTM machine and the fracture was observed using an SEM microscope. The test results showed that the polyester polymer mixed with 30% vinyl ester showed the highest increase in fracture strength, which was equal to K<sub>1c</sub> = 1.67 N.mm<sup>0.5</sup> compared to pure polyester, only K<sub>1c</sub> = 0.77 N.mm<sup>0.5</sup> can increase (216 %). Increasing the mixture content of 30% vinyl ester in polyester will change the brittle nature of unsaturated polyester to become more resilient because the vinyl ester molecules break the bonds of the polyester molecular chains.

Numerical investigation of MHD hybrid nanofluid flow with heat transfer subject to thermal radiation across two coaxial cylinders

Numerically the hybrid nanofluid (HNF) flow comprised of aluminum alloys (AA7072 and AA7075) across to coaxial cylinders is reported in the current analysis. The fluid flow has been examined under the significances of viscous dissipation, thermal radiation, and exponential heat source/sink. The HNF is produced by the addition of AA7072 and AA7075 nanoparticles (NPs) in water. Aluminum alloys are mostly used for the electric module wrapping, electronic machinery, automotive body, solar and wind energy controlling, and energy generation. The flow has been modeled in the form of momentum, continuity, and energy equations. Numerical approach parametric continuation method (PCM) is used to solve the modeled equations. The consequences of flow and energy parameters on the temperature, velocity, skin friction, and Nusselt number have been revealed through figures. It has been noticed that the fluid velocity drops, whereas the energy curve develops with the escalating influence of magnetic field. Furthermore, the rising numbers of AA7072 and AA7075 NPs in the water diminish the fluid velocity and temperature profile. Energy curve accelerates with the growing values of Brinkman number. It can be observed that the energy transmission rate upsurges up to 13.17% by the addition of AA7072 and AA7075 NPs in the water.

Production-related effects on the adhesive bondline performance of structural adhesives joining dissimilar materials

Adhesive bonding is a commonly used technology for joining dissimilar materials. However, production-related effects on the performance of the bondline have to be considered for an accurate joint design. In case of an adhesive joint in an automotive multi-material body in white, these effects arise from the so-called mismatch in thermal expansion coefficients, which leads to distortions of the adhesive in an uncured state or even damage in the cured one. The distortion of the uncured adhesive in the normal direction is called the ‘viscous fingering effect’, which reduces the adhesively bonded cross section by changing the adhesive bondline's shape to thin ‘fingers’ and therefore influences the materials properties. To investigate the effect of viscous fingering on the modulus, strength and energy release rate, linear butt bonded specimens and Tapered Double Cantilever Beams (TDCB) with different elongations of the adhesive bondline in the viscous state are investigated. The results are used to parameterize a cohesive zone model (CZM) and perform numerical analysis of the TDCB specimen for validation and to build up a model of a dissimilar joint consisting of a steel hatprofile and an adhesively bonded aluminum panel subjected to thermal distortions.

Experimental and numerical investigation on the crashworthiness performance of double hat‐section Al‐CFRP beam subjected to quasi‐static bending test

AbstractNowadays, hybrid structures, which combine low‐density composites with low‐cost thin‐walled metals, have shown great effect in enhancing the performance of automotive body structures, especially the energy absorber components. This study focuses on the experimental and numerical investigation of the bending energy absorption behavior of CFRP/aluminum hybrid double hat‐section beams used in the side part of the car body. In the experimental section, two types of double hat‐section beams were fabricated: aluminum and Al/CFRP. These beams were then subjected to quasi‐static three‐point bending tests. The results demonstrated that the hybrid beam exhibited superior energy absorption capabilities compared to the single beam. Subsequently, a finite element model was developed using LS‐Dyna software and was validated by comparing the experimental and numerical load–displacement results. In‐depth numerical analyses were conducted to investigate the influence of various design parameters, including CFRP‐reinforcement configuration, numbers of CFRP layers, CFRP ply‐angle, CFRP reinforced length, and aluminum/CFRP mass, on crashworthiness indicators. The numerical findings indicate that the hybrid beam with , ply‐angles exhibited better crash force efficiency (CFE) and specific energy absorption (SEA) compared to other ply‐angles, respectively. Furthermore, increasing the number of CFRP layers within the total beam's mass improved its energy absorption capacity. It was also revealed that the CFRP length on the upper and lower hats could be considered as 42.5% of the total aluminum beam length, as opposed to the full CFRP length, providing enhanced energy absorption capabilities.Highlights Bending behavior of the Al and Al/CFRP double hat section beams. Effects of variable thickness and identical mass on the double hat section beam. Effects of variable ply angle and number of CFRP layers on the hybrid beams. Discrete effect of CFRP reinforcement configurations and inner CFRP lengths.

Research on joint strength and energy absorption of CFRP and Al sheets bonded-FDS hybrid joining

The application of a composite-metal alloy lightweight body structure is one of the ways to achieve lightweight in an automobile. Materials such as carbon fiber reinforced polymer (CFRP) and aluminum alloys are widely used in the automotive industry due to their excellent performance. However, the significant differences in performance parameters between CFRP and aluminum alloy materials make joining heterogeneous materials challenging. Therefore, a rational joining process is crucial for the development of CFRP–aluminum alloy structures. This study proposes a hybrid joining method that combines flow drill screw (FDS) and adhesive bonding to join commonly used aluminum alloy sheets with CFRP sheets in automotive body manufacturing. Finite element analysis simulations were used to compare and characterize the failure modes of the bonded-FDS hybrid joints in tensile tests. The results were verified for accuracy. Tensile tests were conducted to compare the mechanical performance and failure modes of bonded joints, FDS joints, and hybrid joints. By analyzing the load–displacement curve, it was found that the FDS process in the hybrid joining damages the internal structure of the adhesive layer. However, the joint strength is still higher than that of the single joint strength, and the energy absorption value is about 4.7 times that of the adhesive and 1.6 times that of the FDS. This study provides a new industrial solution and serves as a reference for failure performance in composite material structures in the automotive industry, especially in cases involving one-sided access joining points.

Innovative joining technologies for lightweight material vehicles

The transport industry is one of the most important for society and its economic growth. In Europe, this is especially true for road transport, which is an essential pillar for employment, trade, and economic development. The challenge is to minimize energy and cost and maximize efficiency while ensuring comfort and safety. This is the driving force behind technological progress that with social changes (such as, changing consumer preferences, greater environmental awareness) and political changes is revolutionizing the way people and goods move. Nevertheless, the selection of lightweight materials is negligible; it could involve new manufacturing technologies and joining techniques. Jaguar Land Rover (JLR) has been one of the prominent car producers employing aluminum alloys since 2003. A typical JLR monocoque is characterized by 90% aluminum stampings components made of 5xxx and 6xxx series aluminum alloys. Audi Space Frame (ASF) represents an alternative interpretation of improved lightweight frame architecture, and it is characterized by aluminum for more than 80% with the residual parts in CFRP used for rear panels, tunnel and the components useful to higher torsional stiffness. A 30% weight decrease is reached with respect to traditional steel corresponding elements. This review shows an overview of the challenges and opportunities for automotive body structures in the coming years while maintaining the goal of reducing mass and improving sustainability without increasing costs and impacting safety. This manuscript first evaluates how we can reduce mass in vehicles minimizing the carbon footprint and developing recyclable structures. The potential of new materials will be shown in light of the design constraints and the choice of technology used. The final remarks will discuss opportunities for engineering innovation dictated by this period of great changes and needs.

Effects of Pre-Strain on Bake Hardenability and Precipitation Behavior of Al-Mg-Si Automotive Body Sheets

Effects of Pre-Strain on Bake Hardenability and Precipitation Behavior of Al-Mg-Si Automotive Body Sheets

Research on Human-Machine Collaborative Aesthetic Decision-Making and Evaluation Methods in Automotive Body Design: Based on DCGAN and ANN Models

Research on Human-Machine Collaborative Aesthetic Decision-Making and Evaluation Methods in Automotive Body Design: Based on DCGAN and ANN Models