New Concepts for Polyurethane Foams in Automotive Body Design

1969 ◽  
Author(s):  
William R. White
Keyword(s):  
Polyurethane Foams ◽  
Automotive Body ◽  
New Concepts ◽  
Body Design

scholarly journals Metallurgical Effects of Niobium in Dual Phase Steel

Metals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 504 ◽  
Author(s):  
Hardy Mohrbacher ◽  
Jer-Ren Yang ◽  
Yu-Wen Chen ◽  
Johannes Rehrl ◽  
Thomas Hebesberger
Keyword(s):  
Dual Phase Steel ◽  
Dual Phase ◽  
Steel Matrix ◽  
High Ductility ◽  
Dp Steel ◽  
Industrial Processing ◽  
Automotive Body ◽  
Niobium Microalloying ◽  
Body Design ◽  
Kinetics Of

Dual phase (DP) steels are widely applied in today’s automotive body design. The favorable combination of strength and ductility in such steels is in first place related to the share of ferrite and martensite. The pronounced work hardening behavior prevents localized thinning and allows excellent stretch forming. Niobium microalloying was originally introduced to dual phase steel for improving bendability by refining the microstructure. More recently developed “high ductility” (HD) DP steel variants provide increased drawability aided by a small share of austenite retained in the microstructure. In this variant niobium microalloying produces grain refinement and produces a dispersion of nanometer-sized carbide precipitates in the steel matrix which additionally contributes to strength. This study investigates the microstructural evolution and progress of niobium precipitation during industrial processing of high-ductility DP 980. The observations are interpreted considering the solubility and precipitation kinetics of niobium. The influences of niobium on microstructural characteristics and its contributions to strength and formability are discussed.

Stability and seam variation analysis for automotive body design

2002 ◽  
Vol 13 (2) ◽  
pp. 173-187 ◽  
Author(s):  
Rikard Söderberg ◽  
Lars Lindkvist
Keyword(s):  
Variation Analysis ◽  
Automotive Body ◽  
Body Design

A Mixed-Kernel-Based Support Vector Regression Model for Automotive Body Design Optimization Under Uncertainty

2017 ◽  
Vol 3 (4) ◽  
Author(s):  
Yudong Fang ◽  
Zhenfei Zhan ◽  
Junqi Yang ◽  
Xu Liu
Keyword(s):  
Design Optimization ◽  
Support Vector Regression ◽  
Kernel Function ◽  
Optimization Under Uncertainty ◽  
Polynomial Kernel ◽  
Support Vector ◽  
Fe Model ◽  
Support Vector Regression Model ◽  
Automotive Body ◽  
Body Design

Finite element (FE) models are commonly used for automotive body design. However, even with increasing speed of computers, the FE-based simulation models are still too time-consuming when the models are complex. To improve the computational efficiency, support vector regression (SVR) model, a potential approximate model, has been widely used as the surrogate of FE model for crashworthiness optimization design. Generally, in the traditional SVR, when dealing with nonlinear data, the single kernel function-based projection cannot fully cover data distribution characteristics. In order to eliminate the application limitations of single kernel SVR, a method for reliability-based design optimization (RBDO) based on mixed-kernel-based SVR (MKSVR) is proposed in this research. The mixed kernel is constructed based on the linear combination of radial basis kernel function and polynomial kernel function. Through the particle swarm optimization (PSO) algorithm, the parameters of the mixed kernel SVR are optimized. The proposed method is demonstrated through a representative analytical RBDO problem and a vehicle lightweight design problem. And the comparitive studies for SVR and MKSVR in application indicate that MKSVR surpasses SVR in model accuracy.

scholarly journals Alloy Optimization for Reducing Delayed Fracture Sensitivity of 2000 MPa Press Hardening Steel

Metals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 853 ◽  
Author(s):  
Hardy Mohrbacher ◽  
Takehide Senuma
Keyword(s):  
Tensile Strength ◽  
Hydrogen Embrittlement ◽  
Alloying Elements ◽  
Steel Alloy ◽  
Delayed Fracture ◽  
Press Hardening ◽  
Automotive Body ◽  
Body Design ◽  
Delayed Cracking ◽  
Press Hardening Steel

Press hardening steel (PHS) is widely applied in current automotive body design. The trend of using PHS grades with strengths above 1500 MPa raises concerns about sensitivity to hydrogen embrittlement. This study investigates the hydrogen delayed fracture sensitivity of steel alloy 32MnB5 with a 2000 MPa tensile strength and that of several alloy variants involving molybdenum and niobium. It is shown that the delayed cracking resistance can be largely enhanced by using a combination of these alloying elements. The observed improvement appears to mainly originate from the obstruction of hydrogen-induced damage incubation mechanisms by the solutes as well as the precipitates of these alloying elements.

A Mixed-Kernel-Based Support Vector Regression Model for Automotive Body Design Optimization

2016 ◽  
Author(s):  
Yudong Fang ◽  
Zhenfei Zhan ◽  
Junqi Yang ◽  
Jun Lu ◽  
Chong Chen
Keyword(s):  
Design Optimization ◽  
Kernel Function ◽  
Optimization Design ◽  
Approximate Model ◽  
Polynomial Kernel ◽  
Support Vector ◽  
Fe Model ◽  
Support Vector Regression Model ◽  
Automotive Body ◽  
Body Design

Finite Element (FE) models are commonly used for automotive body design. However, even with increasing speed of computers, the FE-based simulation models are still too time-consuming when the models are complex. To improve the computational efficiency, SVR, a potential approximate model, has been widely used as the surrogate of FE model for crashworthiness optimization design. Generally, in the traditional SVR, when dealing with nonlinear data, the single kernel function based projection can’t fully cover data distribution characteristics. In order to eliminate the limitations of single kernel SVR, a mixed-kernel-based SVR (MKSVR) is proposed in this research. The mixed kernel is constructed based on the linear combination of radial basis kernel function and polynomial kernel function. Through the particle swarm optimization algorithm, the parameters of the mixed kernel SVR are optimized. Then the proposed MKSVR is applied to automotive body design optimization. The application of MKSVR is demonstrated by a vehicle design problem for weight reduction while satisfying safety constraints on X direction acceleration and Crush Distance. A comparison study for SVR and MKSVR in application indicates MKSVR surpasses SVR in model accuracy.

Novel Approaches to Low-Voltage Scanning Electron Microscopy

1990 ◽  
Vol 48 (1) ◽  
pp. 366-367
Author(s):  
Arthur V. Jones
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Low Voltage ◽  
Electron Optics ◽  
Current Interest ◽  
New Concepts ◽  
Opportune Time ◽  
Novel Approaches ◽  
Voltage Scanning ◽  
Scanning Electron

In comparison with the developers of other forms of instrumentation, scanning electron microscope manufacturers are among the most conservative of people. New concepts usually must wait many years before being exploited commercially. The field emission gun, developed by Albert Crewe and his coworkers in 1968 is only now becoming widely available in commercial instruments, while the innovative lens designs of Mulvey are still waiting to be commercially exploited. The associated electronics is still in general based on operating procedures which have changed little since the original microscopes of Oatley and his co-workers.The current interest in low-voltage scanning electron microscopy will, if sub-nanometer resolution is to be obtained in a useable instrument, lead to fundamental changes in the design of the electron optics. Perhaps this is an opportune time to consider other fundamental changes in scanning electron microscopy instrumentation.

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