Forming Potential of Steel/Polymer/Steel Sandwich Composites with Local Plate Inserts

2012 ◽  
Vol 706-709 ◽  
pp. 681-686 ◽  
Author(s):  
Heinz Palkowski ◽  
Olga Sokolova ◽  
Adele Carradò
Keyword(s):  
Deep Drawing ◽  
High Performance ◽  
High Strength ◽  
Metal Plate ◽  
Elastic Behaviour ◽  
Forming Limit ◽  
Sandwich Composites ◽  
Strength And Stiffness ◽  
Naval Engineering ◽  
Forming Behaviour

High-performance metal/polymer/metal hybrid sandwich composites are attractive materials for lightweight constructions in automotive, aerospace and naval engineering world-wide. Due to the excellent combination of mechanical, thermal and elastic properties and, as a result of high forming potential, they can be used in areas of high vibration, where high damping properties of the polymer are demanded and at the same time high strength and stiffness are given by the metal. Disadvantages can be given in case of mechanical or thermal joining of these polymer-based sandwiches because of the elastic behaviour as well as low melting temperature of the polymer. Local metal plate insertions in the soft core at the place of joining can be a solution for such kind of problems. But forming behaviour of sandwich materials with and without local inlays differs strongly. Sandwich composites of that type were produced by roll-bonding. Their quality and their position were controlled by Lockin thermography. The forming behaviour of sandwiches with different geometry, size, type and the position of the inlays was tested by deep drawing and bending and analysed with the help of digital photogrammetry and compared to experimentally obtained mechanical properties. As a result, the local inlays, as well as their geometry, size and type strongly influence the forming limit conditions. The differences in flow behaviour of non-reinforced and reinforced sandwich regions after deep drawing and bending will be presented, as well as the influence of the position of the inlays.

scholarly journals Lightweight in Automotive Components by Forming Technology

2020 ◽  
Vol 3 (3) ◽  
pp. 195-209 ◽  
Author(s):  
Stephan Rosenthal ◽  
Fabian Maaß ◽  
Mike Kamaliev ◽  
Marlon Hahn ◽  
Soeren Gies ◽  
...  
Keyword(s):  
High Performance ◽  
Lightweight Design ◽  
Dissimilar Materials ◽  
Hot Extrusion ◽  
High Strength ◽  
Extrusion Process ◽  
Specific Strength ◽  
Metal Metal ◽  
Fiber Metal ◽  
Strength And Stiffness

AbstractLightweight design is one of the current key drivers to reduce the energy consumption of vehicles. Design methodologies for lightweight components, strategies utilizing materials with favorable specific properties and hybrid materials are used to increase the performance of parts for automotive applications. In this paper, various forming processes to produce light parts are described. Material lightweight design is discussed, covering the manufacturing processes to produce hybrid components like fiber–metal, polymer–metal and metal–metal composites, which can be used in subsequent deep drawing or combined forming processes. Approaches to increasing the specific strength and stiffness with thermomechanical forming processes as well as the in situ control of the microstructure of such components are presented. Structure lightweight design discusses possibilities to plastically form high-strength or high-performance materials like magnesium or titanium in sheet, profile and tube forming operations. To join those materials and/or dissimilar materials, new joining by forming technologies are shown. To economically produce lightweight parts with gears or functional elements, incremental sheet-bulk metal forming is presented. As an important part property, the damage evolution during the forming operations will be discussed to enable even lighter parts through a more reliable design. New methods for predicting and tailoring the mechanical properties like strength and residual stresses will be shown. The possibilities of system lightweight design with forming technologies are presented. A combination of additive manufacturing and forming to produce highly complex parts with integrated functions will be shown. The integration of functions by a hot extrusion process for the manufacturing of shape memory alloys is presented. An in-depth understanding of the newly developed processes, methodologies and effects allows for a more accurate dimensioning of components. This facilitates a reduction in the total mass and an increasing performance of vehicle components.

scholarly journals Production of Customized High-Strength Hybrid Sandwich Structures

2010 ◽  
Vol 137 ◽  
pp. 81-128 ◽  
Author(s):  
Olga Sokolova ◽  
Adele Carradó ◽  
Heinz Palkowski
Keyword(s):  
Deep Drawing ◽  
Steel Plate ◽  
High Strength ◽  
Image Correlation ◽  
Sandwich Composite ◽  
Adhesion Properties ◽  
Mesh Reinforcement ◽  
Four Point Bending ◽  
Reinforced Steel ◽  
Forming Behaviour

The production process and the forming behaviour of locally reinforced steel/polymer/steel (316L/PP-PE/316L) hybrid sandwich composite materials (SMS) have been investigated. The effect of simple plate reinforcements with different size, shape and geometry on the forming limits of SMS was studied. As a local reinforcement, the simple solid steel and mesh steel plate inlays with central and edge positions were chosen instead of a polymer core as a sandwich laminate. In order to increase the adhesion properties between the metal and polymer layers, corona discharge and plasma preliminary surface treatments were applied prior to the sandwich production. Both, deep drawing and stretching cup-forming tests were performed in order to analyse the forming behaviour as well as the failure of SMS with and without local inlays subject to different tensile loadings. The influence of the local reinforcement on the bending behaviour was determined by three and four-point bending processes. Stress-strain curves and thinning behaviour of SMS with local reinforcements under the different forming loads were determined using digital image correlation via photogrammetry. The forming behaviour strongly depends on the quality, geometry and size of the local plate inlays. Owing to the different positions of reinforcement as well as to the different polymer content around of inlays, failure of SMS by bending and drawing differs. The sandwich samples with mesh reinforcement demonstrate better formability by drawing and bending than that of samples with solid plates. In order to minimise the loss in formability of sandwich samples during deep drawing, the size of the centred reinforcement has to be larger than the punch diameter.

scholarly journals Natural Silkworm Cocoon Composites with High Strength and Stiffness Constructed in Confined Cocooning Space

Polymers ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1214 ◽  
Author(s):  
Lan Cheng ◽  
Xiaoling Tong ◽  
Zhi Li ◽  
Zulan Liu ◽  
Huiming Huang ◽  
...  
Keyword(s):  
High Performance ◽  
High Strength ◽  
Homogeneous Layer ◽  
Dense Layer ◽  
Test Results ◽  
Young’S Moduli ◽  
Layer Structures ◽  
Potential Applications ◽  
Silkworm Cocoon ◽  
Strength And Stiffness

In this study, using round paper tubes (PTs) and rectangular cardboard boxes (CBs) as external constraints to control the size of the cocooning space, we fabricated a series of modified silkworm cocoons (PT cocoons and CB cocoons). Their microstructures, morphologies, compositions, and mechanical properties were characterized and compared with normal silkworm cocoons. These two kinds of modified silkworm cocoons exhibit dense and homogeneous layer structures. Tensile test results indicate that above a size limit of cocooning space, their tensile strengths, Young’s moduli, and strain energy densities increase with the decrease in cocooning space. Especially in comparison with the normal cocoons, the tensile strength and Young’s modulus of the PT-14 cocoon increase by 44% and 100%, respectively. Meanwhile, PT cocoons and CB cocoons, except PT-12, also possess better peeling resistance than normal cocoons. Owing to the dense structure and low porosity, the modified cocoons form robust fiber networks that result in high strength and toughness. This study provides a green and efficient method to fabricate mechanically enhanced silkworm cocoons with special shapes and dense layer structures. The method can be easily subjected to further modification processes and has potential applications in the production of high-performance green cocoon composites and biomimetic materials.

High-Performance Polymer Fibers

MRS Bulletin ◽  
1987 ◽  
Vol 12 (8) ◽  
pp. 22-26 ◽  
Author(s):  
W. Wade Adams ◽  
R. K. Eby
Keyword(s):  
Mechanical Properties ◽  
High Performance ◽  
Covalent Bond ◽  
High Strength ◽  
Aromatic Polyamide ◽  
Chain Molecules ◽  
Ordered Array ◽  
New Ideas ◽  
Strong Motivation ◽  
Strength And Stiffness

Since the pioneering work of Carothers which led to the introduction of strong nylon fibers by DuPont in the 1930s, polymer scientists have pursued the development of high-performance fibers to replace natural or metallic products, both to improve mechanical properties and to reduce weight. That development was relatively slow and evenly paced until DuPont again revolutionized the field with the release of Kevlar™, an aromatic polyamide with unprecedented mechanical properties. Since then, the field has literally boomed with new developments, and now organic fibers are available with properties that compete with the best inorganics and are far superior to metal fibers.Strong motivation for the invention of new organic fibers comes from the aerospace industry, which seeks fibers to use in reinforced composite structural materials. Composites bring new advances in stiffness (airplane wings can't bend too much!) in weight savings (every kilogram saved in the structure of an airplane saves $120 over its lifetime, and in a spacecraft $10,000), and in radically new ideas, such as radar-invisibility (stealth)5 and mission-adaptive wings (in-flight variable-shape wings). Hence, for a variety of specialty applications, otherwise commercially indefensible materials become viable.It may be somewhat counter intuitive to materials scientists unfamiliar with polymers to expect polymer mechanical properties to be greater than in the best metals. The origin of high strength and stiffness in a polymer fiber is the covalent bond, especially when aligned in an ordered array of long chain molecules.

Cellulose microfibrils: A novel method of preparation using high shear refining and cryocrushing

Holzforschung ◽  
2005 ◽  
Vol 59 (1) ◽  
pp. 102-107 ◽  
Author(s):  
Ayan Chakraborty ◽  
Mohini Sain ◽  
Mark Kortschot
Keyword(s):  
High Performance ◽  
High Strength ◽  
Cellulose Microfibrils ◽  
Laser Confocal Microscopy ◽  
Novel Technique ◽  
Freeze Dried ◽  
Mechanical Methods ◽  
Novel Method ◽  
Impact Crushing ◽  
Strength And Stiffness

Abstract This paper describes a novel technique to produce cellulose microfibrils through mechanical methods. The technique involved a combination of severe shearing in a refiner, followed by high-impact crushing under liquid nitrogen. Fibers treated in this way were subsequently either freeze-dried or suspended in water. The fibers were characterized using SEM, TEM, AFM, and high-resolution optical microscopy. In the freeze-dried batch, 75% of the fibrils had diameters of 1 μm and below, whereas in the water dispersed batch, 89% of the fibrils had diameters in this range. The aspect ratio of the microfibrils ranged between 15 and 55 for the freeze-dried fibrils, and from 20 to 85 for the fibrils dispersed in water. These measurements suggest that the microfibrils have the potential to produce composites with high strength and stiffness for high-performance applications. The microfibrils in water were compounded with polylactic acid polymer to form a biocomposite. Laser confocal microscopy showed that the microfibrils were well dispersed in the polymer matrix.

Research on Hysteretic Model of SRHSHPC Frame Joints Considering Accumulative Damage

2010 ◽  
Vol 450 ◽  
pp. 227-230
Author(s):  
Shan Suo Zheng ◽  
Fei Yu ◽  
Bin Wang ◽  
Hong Ren Zhang ◽  
Yi Hu
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Damage Index ◽  
High Strength ◽  
Stiffness Degradation ◽  
Hysteretic Model ◽  
Scale Models ◽  
Reversed Loading ◽  
Strength And Stiffness ◽  
Reduced Scale

To reflect the effects of accumulative damage of steel reinforced high strength and high performance concrete (SRHSHPC) frame joints on its mechanical properties such as strength and stiffness degradation under reversed load, a damage index (D) is introduced into hysteretic model of SRHSHPC frame joints. Then a trilinear load-displacement hysteretic model of SRHSHPC frame joints considering accumulative damage is proposed, which can reveal strength and stiffness degradation of SRHSHPC frame joints. Five 1:4 reduced-scale models of SRHSHPC frame joints were constructed and subjected to low cyclic reversed loading to gain the value of those parameters in the D. The calculated results tally with the experimental results well, and it is showed that the proposed hysteretic model considering accumulative damage has a considerable precision.

scholarly journals An investigation of the Formability Behaviour of High Strength Aluminium Alloys Using Different Heat Assisted Forming Processes

2021 ◽  
Author(s):  
M. Schmiedt ◽  
J.M. Schlosser ◽  
R. Schneider ◽  
W. Rimkus ◽  
D.K. Harrison
Keyword(s):  
Sheet Metal ◽  
Aluminium Alloys ◽  
High Strength ◽  
Forming Limit ◽  
Forming Process ◽  
Sheet Metal Parts ◽  
Specific Strength ◽  
Geometrical Complexity ◽  
Process Route ◽  
Forming Behaviour

The usage of ultra-high strength aluminium alloys (EN AW-7000 series) offers a great weight saving potential due to the high rigidity and specific strength values. Various heat assisted forming technologies have been developed in order to improve the limited formability at room temperature and thus to be able to increase the geometrical complexity of such sheet metal parts. In this study the forming behaviour of EN AW-7021 sheet metal alloy is described as a function of the forming process and the corresponding temperature profile. The forming limit curves (FLCs) are obtained by experimental Nakajima tests using the Warmforming, Hotforming, extended Hotforming and W-Temper process route. For this purpose, a Nakajima testing tool is designed according to ISO 12004 standard which allows operating temperatures of up to 200 °C.

Seismic Damage Analysis of SRHSHPC Frame Beams

2012 ◽  
Vol 166-169 ◽  
pp. 2001-2004
Author(s):  
Bin Wang ◽  
Shansuo Zheng ◽  
Fei Yu
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Design Method ◽  
Damage Model ◽  
High Strength ◽  
Seismic Damage ◽  
Stiffness Degradation ◽  
Earthquake Resistant Design ◽  
Study Results ◽  
Strength And Stiffness

Based on the test results of steel reinforcement high strength high performance concrete (SRHSHPC) frame beams, a new seismic damage model of SRHSHPC frame beams considered the strength and stiffness degradation was proposed, which was a non-linear combination of the deformation and accumulative damage. The results can more clearly reflect the laws of strength and stiffness degradation of SRHSHPC frame beams under reversed loading. The study results can supply the theory support for the seismic damage assessment and the establishment of damage-based earthquake-resistant design method of SRHSHPC members.

Curvature Based Forming Limit Prediction of High-Strength Steel Components with Superimposed Stretching and Bending in the Deep Drawing Process

2015 ◽  
Vol 651-653 ◽  
pp. 181-186 ◽  
Author(s):  
Daniela Schalk-Kitting ◽  
Wolfgang Weiß ◽  
Bettina Suhr ◽  
Michael Koplenig
Keyword(s):  
Deep Drawing ◽  
Research Work ◽  
High Strength Steels ◽  
High Strength ◽  
Forming Limit ◽  
Limit Curve ◽  
Forming Limit Curve ◽  
Bending Tests ◽  
Advanced High Strength Steels ◽  
Stretch Bending

The state of deformation in deep drawing operations is characterized by superimposed stretching and bending (i.e. stretch-bending). Bending effects, especially for Advanced High Strength Steels (AHSS) are known to influence the material formability. Traditional formability measures such as the Forming Limit Curve (FLC) fail to reliably predict stretch-bending formability. Consequently, to ensure an efficient and economical use of AHSS in the industrial application, current research work is focusing on the reliable numerical prediction of stretch-bending formability of AHSS sheets.Within this work, a phenomenological concept to predict the forming limit (e.g. the onset of necking) in deep drawing processes taking bending effects into account is presented. The proposed concept is based on curvature-dependent (i.e. regarding the principle curvatures κ1 and κ2 of the stretch-bend (convex) sheet surface) forming limit surfaces representing the probability of failure and is calibrated with experimental results from stretch-bending tests and conventional forming test such as a Nakazima test. The results of the phenomenological forming limit criterion are promising and show a more accurate prediction of the drawing depth at failure than the conventional FLC approach. The method contributes also to a probabilistic view on the forming limit of deep drawing parts.

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