Elastic Energy Absorption of Origami-Based Corrugations

2017 ◽  
Author(s):  
Sean S. Tolman ◽  
Spencer P. Magleby ◽  
Larry L. Howell
Keyword(s):  
Energy Absorption ◽  
Elastic Energy ◽  
Virtual Work ◽  
Compliant Mechanism ◽  
Analytical Models ◽  
Geometrical Parameters ◽  
Work Analysis ◽  
Physical Testing ◽  
Energy Absorbing ◽  
Mechanism Theory

The mechanical properties of origami tessellations may provide innovative new designs for energy absorbing applications. The elastic energy absorbing properties of a particular tesselation, the Miura-ori, is investigated. Analytical models for the kinematics and force-deflection of a unit cell based on two different modes of elastic energy absorption are derived. The force-deflection model is developed based on the application of compliant mechanism theory and virtual work analysis. The models are verified through comparison with published results for similar models, analysis using commercial kinematics software and comparison to physical testing. Physical prototypes are used to determine values stiffness terms. The analytical models are used to explore the effects of the key geometrical parameters of the tessellation. This work lays a foundation for the use of origami-based corrugations in elastic energy absorption applications.

Functionally Graded Cellular Contact-Aided Compliant Mechanism for Energy Absorption

2018 ◽  
Author(s):  
Jovana Jovanova ◽  
Angela Nastevska ◽  
Mary Frecker
Keyword(s):  
Energy Absorption ◽  
Material Properties ◽  
Compliant Mechanisms ◽  
Compliant Mechanism ◽  
Functionally Graded ◽  
Nonlinear Material ◽  
Load Path ◽  
Cellular Contact ◽  
Overall Performance ◽  
Energy Absorbing

Cellular contact-aided compliant mechanisms (C3M) are cellular structures with integrated self-contact mechanisms, i.e. the segments can come into contact with each other during deformation. The contact changes the load path and can influence on the mechanism’s performance. Cellular contact-aided compliant mechanisms can be tailored for a specific structural application, such as energy absorption. Nickel Titanium compliant mechanisms can exploit the superelastic effect to improve performance and increase energy absorption. The potential for compliant mechanisms designed specifically for metal additive manufacturing opens the possibility of functional grading and tailoring the material properties locally for achieving overall performance. The combined effort of the geometry and the nonlinear material property increases the local compliance of the unit cell, resulting in higher energy absorption. A functionally graded 3D energy absorbing contact-aided compliant mechanisms cell with curved walls is analyzed. Functionally graded zones of higher flexibility are explored with different superelastic material properties. Introducing different moduli of elasticity as a function of the critical transformation stress results in different energy absorption. This approach can be used for tailoring the overall performance based on the application.

Dynamic crashing behavior of thin-walled conical tubular structures with nonlinearly-graded diameters

2018 ◽  
Vol 233 (7) ◽  
pp. 2456-2466 ◽  
Author(s):  
Fengxiang Xu ◽  
Suo Zhang ◽  
Kunying Wu
Keyword(s):  
Energy Absorption ◽  
Absorption Capacity ◽  
Geometrical Parameters ◽  
Tubular Structures ◽  
Power Law Distribution ◽  
Thin Walled Structures ◽  
Conical Structure ◽  
Thin Walled ◽  
Energy Absorbing ◽  
Effective Design

Thin-walled structures with graded property have been paid more attention in recent years due to their significant balance between lightweight and crashworthiness. However, few studies have been focused on energy absorption capacity of thin-walled conical tubes with graded diameters. In this paper, the thin-walled conical aluminum tubes with nonlinearly-graded diameters are introduced and their corresponding crashing characteristics are performed. The diameters are assumed to nonlinearly vary according to a power-law distribution function primarily determined by a graded exponent n. It is found that the total weight of thin-walled conical tubes decreases with the increasing of the gradient exponent. The energy-absorbed performances such as specific energy absorption, initial peak crashing force, and mean crashing force of those graded tubular structures are numerically analyzed. And then the effects of various geometric parameters such as the gradient exponent, deformation distance, and diameter range on crashing behaviors are further evaluated. It is observed that those parameters especially the gradient exponent has significantly obvious effects on crashworthiness of the proposed nonlinearly graded tubes. It is also noted that the straight conical structure with gradient n = 1.0 may not show the best energy absorption characteristics compared with other gradients. The work could provide valuable information for effective design of thin-walled energy-absorbing structures with variable geometrical parameters.

Mathematical modeling of elastoplastic deformation of tubular energy-absorbing elements under static and impact loading

2020 ◽  
pp. 78-82
Author(s):  
A.Р. Evdokimov ◽  
A.N. Gromyiko ◽  
A.A. Mironov
Keyword(s):  
Mathematical Modeling ◽  
Impact Loading ◽  
Elastoplastic Deformation ◽  
Shock Absorber ◽  
Analytical Models ◽  
Dynamic Impact ◽  
Shock Absorbers ◽  
Energy Absorbing ◽  
Absorbing Elements

Analytical models of static and dynamic impact elastoplastic deformation of tubular energy-absorbing elements constituting a tubular plastic shock absorber are proposed. The developed models can be used for the calculation and design of these shock absorbers. Keywords static and dynamic elastoplastic deformation, mathematical modeling, tubular energy-absorbing element, tubular plastic shock absorber, impact loading. [email protected]

Parameter Characterization for Elastic Energy Absorption of an Embedded Corrugated Wave Padding Concept

2016 ◽  
Author(s):  
Sean S. Tolman ◽  
Amanda Beatty ◽  
Anton E. Bowden ◽  
Larry L. Howell
Keyword(s):  
Energy Absorption ◽  
Cross Section ◽  
Peak Pressure ◽  
Force Distribution ◽  
Finite Element Analyses ◽  
Performance Metric ◽  
Physical Testing ◽  
Physical Tests ◽  
Factorial Design Of Experiments ◽  
Full Factorial

The parameters of an innovative padding concept were investigated using Finite Element Analyses (FEA) and physical testing. The concept relies on a compliant corrugation embedded in an elastic foam to provide stiffness for force distribution and elastic deformation for energy absorption. The shape of the corrugation cross section was explored as well as the wavelength and amplitude by employing a full factorial design of experiments. FEA results were used to choose designs for prototyping and physical testing. The results of the physical tests were consistent with the FEA predictions although the FEA tended to underestimate the peak pressure compared to the physical tests. A performance metric is proposed to compare different padding configurations. The concept shows promise for sports padding applications. It may allow for designs which are smaller, more lightweight, and move better with an athlete than current technologies yet still provide the necessary protective functions.

Design for Additive Manufacturing of Cellular Compliant Mechanism Using Thermal History Feedback

2018 ◽  
Author(s):  
Jivtesh Khurana ◽  
Bradley Hanks ◽  
Mary Frecker
Keyword(s):  
Additive Manufacturing ◽  
Energy Absorption ◽  
Thermal History ◽  
Test Problem ◽  
Compliant Mechanisms ◽  
Compliant Mechanism ◽  
Absorption Capacity ◽  
Unit Cell ◽  
Design For Additive Manufacturing ◽  
Area Of Interest

With growing interest in metal additive manufacturing, one area of interest for design for additive manufacturing is the ability to understand how part geometry combined with the manufacturing process will affect part performance. In addition, many researchers are pursuing design for additive manufacturing with the goal of generating designs for stiff and lightweight applications as opposed to tailored compliance. A compliant mechanism has unique advantages over traditional mechanisms but previously, complex 3D compliant mechanisms have been limited by manufacturability. Recent advances in additive manufacturing enable fabrication of more complex and 3D metal compliant mechanisms, an area of research that is relatively unexplored. In this paper, a design for additive manufacturing workflow is proposed that incorporates feedback to a designer on both the structural performance and manufacturability. Specifically, a cellular contact-aided compliant mechanism for energy absorption is used as a test problem. Insights gained from finite element simulations of the energy absorbed as well as the thermal history from an AM build simulation are used to further refine the design. Using the proposed workflow, several trends on the performance and manufacturability of the test problem are determined and used to redesign the compliant unit cell. When compared to a preliminary unit cell design, a redesigned unit cell showed decreased energy absorption capacity of only 7.8% while decreasing thermal distortion by 20%. The workflow presented provides a systematic approach to inform a designer about methods to redesign an AM part.

scholarly journals Energy Absorption Characteristics of Foam Filled Tri Circular Tube under Bending Loads

2021 ◽  
Vol 15 ◽  
pp. 159-164
Author(s):  
Fauzan Djamaluddin
Keyword(s):  
Energy Absorption ◽  
Failure Modes ◽  
Circular Tube ◽  
Comparative Investigation ◽  
Tubular Structures ◽  
Vehicle Engineering ◽  
Bending Resistance ◽  
Bending Loads ◽  
Foam Filled ◽  
Energy Absorbing

In this study, the researcher carried out a comparative investigation of the crashworthy features of different tubular structures with a quasi-static three bending point, like the foam-filled two and tri circular tube structures. Energy absorption capacities and failure modes of different structures are also studied. Furthermore, the general characteristics are investigated and compared for instance the energy absorption, specific energy absorption and energy-absorbing effectiveness for determining the potential structural components that can be used in the field of vehicle engineering. Experimental results indicated that under the bending conditions, the tri foam-filled structures were higher crashworthiness behaviour than the two foam-filled circular structures. Therefore, this study recommended the use of crashworthy structures, such as foam-filled tri circular tubes due to the increased bending resistance and energy-absorbing effectiveness.

scholarly journals Residue-Residue Mutual Work Analysis of Retinal-Opsin Interaction in Rhodopsin: Implications for Protein-Ligand Binding

2019 ◽  
Author(s):  
Wenjin Li
Keyword(s):  
Virtual Work ◽  
Interaction Matrix ◽  
Time Interval ◽  
Transition Path ◽  
Transition Path Sampling ◽  
Decomposition Approach ◽  
Work Analysis ◽  
Nmr Study ◽  
The Matrix ◽  
Dynamics Simulations

AbstractEnergetic contributions at single-residue level to retinal-opsin interaction in rhodopsin were studied by combining molecular dynamics simulations, transition path sampling, and a newly developed energy decomposition approach. The virtual work at an infinitesimal time interval was decomposed into the work components on one residue due to its interaction with another residue, which were then averaged over the transition path ensemble along a proposed reaction coordinate. Such residue-residue mutual work analysis on 62 residues within the active center of rhodopsin resulted in a very sparse interaction matrix, which is generally not symmetric but anti-symmetric to some extent. 14 residues were identified to be major players in retinal relaxation, which is in excellent agreement with an existing NMR study. Based on the matrix of mutual work, a comprehensive network was constructed to provide detailed insights into the chromophore-protein interaction from a viewpoint of energy flow.

scholarly journals Novel cellular materials for energy absorption applications

2020 ◽  
Author(s):  
Mohammed Mudassir ◽  
Mahmoud Mansour
Keyword(s):  
Additive Manufacturing ◽  
Energy Absorption ◽  
Metal Foams ◽  
Cellular Materials ◽  
Cellular Structures ◽  
Senior Project ◽  
Key Factor ◽  
Good Energy ◽  
To Come ◽  
Energy Absorbing

Cellular materials such as metal foams are porous, lightweight structures that exhibit good energy absorption properties. They have been used for many years in various applications including energy absorption. Traditional cellular structures do not have consistent pore sizes and their behaviors and properties such as failure mechanisms and energy absorption are not always same even within the same batch. This is a major obstacle for their applications in critical areas where consistency is required. With the popularity of additive manufacturing, new interest has garnered around fabricating metal foams using this technology. It is necessary to study the possibility of designing cellular structures with additive manufacturing and their energy absorbing behavior before any sort of commercialization for critical applications is contemplated. The primary hypothesis of this senior project is to prove that energy absorbing cellular materials can be designed. Designing in this context is much like how a car can be designed to carry a certain number of passengers. To prove this hypothesis, the paper shows that the geometry is a key factor that affects energy absorption and that is possible to design the geometry in order to obtain certain behaviors and properties as desired. Much like designing a car, it requires technical expertise, ingenuity, experience and learning curve for designing cellular structures. It is simple to come with a design, but not so much when the design in constrained by stringent requirements for energy absorption and failure behaviors. The scope was limited to the study of metal foams such as the ones made from aluminum and titanium. The primary interest has been academic rather than finding ways to commercialize it. The study has been carried out using simulation and experimental verification has been suggested for future work. Nevertheless, the numerical or simulation results show that energy absorbing cellular structures can be designed that exhibit good energy absorption comparable to traditional metal foams but perhaps with better consistency and failure behaviors. The specific energy absorption was found to be 18 kJ/kg for aluminum metal foams and 23 kJ/kg for titanium metal foams. The average crushing force has been observed to be around 70 kN for aluminum and around 190 kN for titanium. These values are within the acceptable range for most traditional metal foams under similar conditions as simulated in this paper.

scholarly journals Reversed-torsion-type crush energy absorption structure and its inexpensive partial-heating torsion manufacturing method based on origami engineering

2021 ◽  
pp. 1-31
Author(s):  
Xilu Zhao ◽  
Chenghai Kong ◽  
Yang Yang ◽  
Ichiro Hagiwara
Keyword(s):  
Energy Absorption ◽  
Peak Load ◽  
Point Of View ◽  
Building Structures ◽  
Manufacturing Method ◽  
Partial Heating ◽  
Vehicle Structure ◽  
Energy Absorbers ◽  
Energy Absorbing ◽  
Origami Engineering

Abstract Current vehicle energy absorbers face two problems during a collision in that there is only a 70% collapse in length and there is a high initial peak load. These problems arise because the presently used energy-absorbing column is primitive from the point of view of origami. We developed a column called the Reversed Spiral Origami Structure (RSO), which solves the above two problems. However, in the case of existing technology of the RSO, the molding cost of hydroforming is too expensive for application to a real vehicle structure. We therefore conceive a new structure, named the Reversed Torsion Origami Structure (RTO), which has excellent energy absorption in simulation. We can thus develop a manufacturing system for the RTO cheaply. Excellent results are obtained in a physical experiment. The RTO can replace conventional energy absorbers and is expected to be widely used in not only automobile structures but also building structures.

Composite Core Cross Tube Crushing Analysis

2020 ◽  
Author(s):  
Sean Jenson ◽  
Muhammad Ali ◽  
Khairul Alam
Keyword(s):  
Energy Absorption ◽  
Compressive Loading ◽  
Deformation Mode ◽  
High Energy ◽  
Absorption Capacity ◽  
Functionally Graded ◽  
Layer By Layer ◽  
Thin Walled ◽  
The Cross ◽  
Energy Absorbing

Abstract Thin walled axial members are typically used in automobiles’ side and front chassis to improve crashworthiness of vehicles. Extensive work has been done in exploring energy absorbing characteristics of thin walled structural members under axial compressive loading. The present study is a continuation of the work presented earlier on evaluating the effects of inclusion of functionally graded cellular structures in thin walled members under axial compressive loading. A compact functionally graded composite cellular core was introduced inside a cross tube with side length and wall thickness of 25.4 mm and 3.048 mm, respectively. The parameters governing the energy absorbing characteristics such as deformation or collapsing modes, crushing/ reactive force, plateau stress level, and energy curves, were evaluated. The results showed that the inclusion of composite graded cellular structure increased the energy absorption capacity of the cross tube significantly. The composite graded structure underwent progressive stepwise, layer by layer, crushing mode and provided lateral stability to the cross tube thus delaying local tube wall collapse and promoting large localized folds on the tube’s periphery as compared to highly localized and compact deformation modes that were observed in the empty cross tube under axial compressive loading. The variation in deformation mode resulted in enhanced stiffness of the composite structure, and therefore, high energy absorption by the structure. This aspect has a potential to be exploited to improve the crashworthiness of automobile structures.

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