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Technical Paper

Prediction of Ductile Fracture Propagation of High Strength Steels in Automotive Structures

2019-04-02
2019-01-1097
Initiation and propagation of ductile fractures in crashed automotive components using high strength steels are investigated in order to understand the mechanism of the fracture propagation. The fracture is often prone to occur at sheet edge in strain concentration zone at crash deformation. The fracture is extended intricately to inside of the structure, with the influence local stress and strain field. It is very important to predict the fracture initiation and propagation under crashed deformation for the reliable design of the light-weight structural by using ultra-high strength steels. In this study, 3-point bending tests are carried out with a hat-shaped part which have a notch and a hole to induce fracture. Three types of notch are machined by wire cut electric discharge process. The hole is located near the notch to investigate the influence on fracture propagation.
Technical Paper

Effects of Nitrided and Chrome Plated Die Surface Roughness on Friction in Bending Under Tension

2019-04-02
2019-01-1093
Different die surface polish conditions result in a noticeable effect on material flow in stamping, which can lead to splitting, wrinkling, or other surface stretching issues associated with different friction conditions. These occurrences are not only limited to the non-coated dies, but also nitrided and chrome plated dies. To ensure quality control of the stamped parts, the die conditions corresponding to different polishing procedures need to be developed based on measurable parameters such as surface roughness (Ra). The intent of this study is to investigate the effects of nitrided and chrome plated die surface roughness on friction. The Bending-Under-Tension (BUT) test was conducted to simulate the stamping process due to the test’s versatility and flexibility in changing test parameters. The test involves moving sheet metal across a 3/8-inch diameter pin, which substitutes for a die surface. The pin can be modified by material, heat treatment, coating, and surface roughness.
Technical Paper

Strain Rate Effect on Martensitic Transformation in a TRIP Steel Containing Carbide-Free Bainite

2019-04-02
2019-01-0521
Adiabatic heating during plastic straining can slow the diffusionless shear transformation of austenite to martensite in steels that exhibit transformation induced plasticity (TRIP). However, the extent to which the transformation is affected over a strain rate range of relevance to automotive stamping and vehicle impact events is unclear for most third-generation advanced high strength TRIP steels. In this study, an 1180MPa minimum tensile strength TRIP steel with carbide-free bainite is evaluated by measuring the variation of retained austenite volume fraction (RAVF) in fractured tensile specimens with position and strain. This requires a combination of servo-hydraulic load frame instrumented with high speed stereo digital image correlation for measurement of strains and ex-situ synchrotron x-ray diffraction for determination of RAVF in fractured tensile specimens.
Technical Paper

FD&E Total Life T-Sample Residual Stress Analytical Predictions and Measured Results

2019-04-02
2019-01-0528
The Society of Automotive Engineers Fatigue Design & Evaluation Committee [SAE FD&E] is actively working on a total life project for weldments, in which the welding residual stress is a key contributor to an accurate assessment of fatigue life. Physics-based welding process simulation and various types of residual stress measurements were pursued to provide a representation of the residual stress field at the failure location in the fatigue samples. A well-controlled and documented robotic welding process was used for all sample fabrications to provide accurate inputs for the welding simulations. One destructive (contour method) residual stress measurement and several non-destructive residual stress measurements-surface X-ray diffraction (XRD), energy dispersive X-ray diffraction (EDXRD), and neutron diffraction (ND)-were performed on the same or similarly welded samples.
Technical Paper

Head and Neck Loading Conditions over a Decade of IIHS Rear Impact Seat Testing

2019-04-02
2019-01-1227
Rear-end impacts are the most common crash scenario in the United States. Although automated vehicle (AV) technologies, such as frontal crash warning (FCW) and automatic emergency braking (AEB), are mitigating and preventing rear-end impacts, the technology is only gradually being introduced and currently has only limited effectiveness. Accordingly, there is a need to evaluate the current state of passive safety technologies, including the performance of seatbacks and head restraints. The objective of this study was to examine trends in head and neck loading during rear impact testing in new vehicle models over the prior decade. Data from 601 simulated rear impact sled tests (model years 2004 to 2018) conducted as a part of the Insurance Institute for Highway Safety (IIHS) Vehicle Seat/Head Restraint Evaluation Protocol were obtained.
Technical Paper

Development of Plastic Region Tightening 1.6-GPa Ultra-High Strength Bolt with High Delayed Fracture Resistance

2019-04-02
2019-01-1116
A new variable compression turbo (VC-Turbo) engine, which has a multi-link system for controlling the compression ratio from 8:1 to 14:1, requires high axial force for fastening the multi-links because of high input loads and the downsizing requirement. Therefore, it was necessary to develop a 1.6-GPa tensile strength bolt with plastic region tightening. One of the biggest technical concerns is delayed fracture. In this study, quenched and tempered alloy steels were chosen for the 1.6-GPa tensile strength bolt.
Technical Paper

Experimental Drawbeads Design Research

2019-04-02
2019-01-1087
In order to constrain the restraining force and control the speed of metal flow, drawbeads are widely used in industry. They prevent wrinkling or necking in formed panels, reduce the binder force, and minimize the usage of sheet metal to make a part. Different drawbead configurations can satisfy various stamping production. Besides local design of drawbeads, other factors like pulling directions, binder angles and single or multiple beads play an important role too. Moreover, it was found that the same beads configuration can own a different rate of change of pulling force on different gaps by experience. In this paper, to study the effect of each factor, the Aluminum and Steel sheet metals were tested to obtain the pulling force as they passed through a draw bead. Three gap cases between a male and a female beads are set to figure out the trend of pulling force.
Technical Paper

Prediction and Validation of Unknown GISSMO Properties Using by Regression Analysis of Experimental Damage Tests

2019-03-25
2019-01-1426
A seat, as one of the main automobile components is closely related to the passenger safety. It plays an important role on a protection of passengers from a sudden movement of a car and external front/rear/side crash. In order to achieve these purposes, strength, rigidity and durability of a seat have to be satisfied which are regulated by the law. Therefore, a prediction of the fracture time and the behavior of the seat structure by Finite Element analysis are very important. However, the fracture prediction method from axial tensile strength test has limits to present the behavior which is obtained in multiple loading cases. For this reason, a new analysis method for the fracture prediction considering multiple loading cases has to be established. In this research, the phenomenon of a seat fracture is implemented and the simulation is performed to predict the behavior using GISSMO Damage model in LS-DYNA.
Technical Paper

Characterization of Carbon Fiber and Glass Fiber’s Micro and Nanostructure Using Electron Microscopy, Raman Spectroscopy and XRD Analysis

2019-03-25
2019-01-1441
Nowadays, most manufacturers are looking for the improvement of lightweight parts and other components in the automobile field. Carbon fiber and glass fiber are the most effective materials for their requirement to reduce the weight in vehicles due to their light weight and high tensile strength. The diameter of carbon fiber is 6 μm while glass fiber diameter is 17 μm. The mechanical tensile force of carbon fiber and glass fiber are 430 N and 290 N respectively on fiber alone without matrix. Carbon fibers are gradually smaller in each filament due to tensile force. Approximately 5 mm are elongated for both carbon fiber and glass fiber in tensile test report. In current research, characteristic and tensile force of carbon fiber and glass fiber were investigated by using electron microscopy, Raman spectroscopy and XRD.
Standard

Electroless Nickel-Boron Plating

2019-03-18
CURRENT
AMS2399C
This specification covers the engineering requirements for electroless deposition of nickel-boron on various materials and the properties of the deposit.
Standard

Individual Inflatable Life Preservers

2019-03-18
CURRENT
ARP1354B
This Aerospace Recommended Practice (ARP) provides criteria for operational characteristics to be considered in the design of individual, inflatable life preservers intended for air transport safety.
Standard

Heat Treatment, Precipitation-Hardening Corrosion-Resistant, Maraging, and Secondary Hardening Steel Parts

2019-03-14
WIP
AMS2759/3J
This specification, in conjunction with the general requirements for steel heat treatment covered in AMS2759, establishes the requirements for heat treatment of precipitation-hardening corrosion-resistant, maraging and secondary hardening, steel parts. Parts are defined in AMS2759. Parts made from steels other than those specified in this specification may be heat treated in accordance with the applicable requirements herein using processing temperatures, times, and other parameters recommended by the material producer unless otherwise specified by the purchaser. General ordering instructions are specified in AMS2759.
Standard

350 °F Autoclave Cure, Low Flow Toughened Epoxy Prepregs, Type 38, Class 2, Grade 193, Style 3K-70-PW, Fiber 1

2019-03-12
WIP
AMS3961/1A
The intent of this specification is for the procurement of the material listed on the QPL and, therefore, no qualification or equivalency threshold values are provided. Users that intend to conduct a new material qualification or equivalency program shall refer to the Quality Assurance section of the base specification, AMS3961. All material qualification and equivalency data has been archived and is available for review upon request. Contact the CMH-17 Secretariat (www.cmh17.org) for additional information.
Standard

350 °F Autoclave Cure, Low Flow Toughened Epoxy Prepregs, Type 35, Class 1, Grade 190, Fiber 2

2019-03-12
WIP
AMS3961/2A
The intent of this specification is for the procurement of the material listed on the QPL and, therefore, no qualification or equivalency threshold values are provided. Users that intend to conduct a new material qualification or equivalency program shall refer to the Quality Assurance section of the base specification, AMS3961. All material qualification and equivalency data has been archived and is available for review upon request. Contact the CMH-17 Secretariat (www.cmh17.org) for additional information.
Standard

350 °F Autoclave Cure, Low Flow Toughened Epoxy Prepregs, Type 35, Class 1, Grade 190, Fiber 1

2019-03-12
WIP
AMS3961/3A
The intent of this specification is for the procurement of the material listed on the QPL and, therefore, no qualification or equivalency threshold values are provided. Users that intend to conduct a new material qualification or equivalency program shall refer to the Quality Assurance section of the base specification, AMS3961. All material qualification and equivalency data has been archived and is available for review upon request. Contact the CMH-17 Secretariat (www.cmh17.org) for additional information.
Standard

Fuel and Oil Hoses

2019-03-12
WIP
J30
This SAE standard covers fuel, oil, or emission hose for use in coupled and uncoupled applications, for use with gasoline, oil, diesel fuel, lubrication oil, or the vapors present in either the fuel system or in the crankcase of internal combustion engines in mobile or stationary applications. This standard covers the hose portion only. If assembly / coupling is required, that is to be agreed to between the customer and assembler, along with the specific requirements.
Standard

Fitting, Plug-in Union, Ring Locked, 24° Cone, Fluid Connection, 5080 psi (35 000 kPa), Specification for

2019-03-07
WIP
AS5000E
This SAE Aerospace Standard (AS) establishes the requirements for 24 degree cone AS5827 or EN 6123 flareless Ring locked fitting assemblies per AS5550 and AS5865, for use in aircraft fluid systems at nominal operating pressure of 5080 psi (35 000 kPa) maximum and operating temperature range of -65 to +275 °F (-54 to +135 °C). The general requirements shall be for, but not limited to, commercial aircraft hydraulic components per AS4941, using port configuration as specified in AS5551.
Standard

Elastomer: Silicone Rubber (MQ/VMQ) General Purpose 45 - 55 Durometer Type “A” Hardness

2019-02-28
CURRENT
AMS3302J
This specification covers a silicone (MQ/VMQ) elastomer that can be used to manufacture product in the form of sheet, strip, tubing, extrusions, and molded shapes. This specification should not be used for molded rings, compression seals, O-ring cord, and molded in place gaskets for aeronautical and aerospace applications without complete consideration of the end use prior to the selection of this material.
Standard

Elastomer: Fluorosilicone Rubber (FVMQ) Fuel and Oil Resistant 75 - 85 Durometer Type “A” Hardness For Products in Fuel Systems/Lubricating Oils

2019-02-28
CURRENT
AMS3741
This specification covers a fluorosilicone (FVMQ) elastomer that can be used to manufacture product in the form of sheet, strip, tubing, extrusions, and molded shapes. This specification should not be used for molded rings, compression seals, O-ring cord, and molded in place gaskets for aeronautical and aerospace applications without complete consideration of the end use prior to the selection of this material.
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