Effects of Aging of Polyurethane Foams in the Context of Furniture Design

Smardzewski, Jerzy; Matwiej, Łukasz

doi:10.5552/drind.2013.1241

Cited by 8 publications

(5 citation statements)

References 6 publications

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“…Foam rubber is characterized by a Young modulus E = 30 kPa and a Poisson ratio ν = 0.1 (Table S1 and Figure S1 in Supporting Information S1). Due to the low stress applied, the foam wedge is subject to particularly low strains (ε < 0.02), excluding possible nonlinearities in its deformation (Smardzewski et al, 2008). The analog fault zone is a generic model of natural subduction shear zones.…”

Section: Rheological and Frictional Properties Of Analog Materialsmentioning

confidence: 99%

Foamquake: A Novel Analog Model Mimicking Megathrust Seismic Cycles

et al. 2022

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In the last decades, seismotectonic analog models have been developed to better understand many aspects of the seismic cycle. Differently from other lab‐quake experiments, seismotectonic models mimic the first order characteristics of the seismic cycle in a scaled fashion. Here we introduce Foamquake: A novel seismotectonic model with a granular frictional interface that as a whole behaves elastoplastically. The model experiences cycles of elastic loading and release via spontaneous nucleation of frictional instabilities at the base of an elastic foam wedge, hereafter called foamquakes. These analog earthquakes show source parameters (i.e., moment‐duration and moment‐rupture area) scaling as great interplate earthquakes and a coseismic displacement of few tens of meters when scaled to nature. Models with two asperities separated by a barrier can be performed with Foamquake given the 3D nature of the setup. Such model configuration generates sequences of full and partial ruptures with different recurrence intervals as well as rupture cascades. By tuning the normal load acting on individual asperities, Foamquake reproduces superimposed cycles rupture patterns such as those observed along natural megathrusts. The physical properties of asperities and barriers affect model seismic behavior. Asperities with similar properties and low yield strength fail preferentially in a simultaneous manner. The combination of all those characteristics suggests that Foamquake is a valuable tool for investigating megathrust seismicity and seismic processes that depend on the 3D nature of the subduction environment.

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Section: Rheological and Frictional Properties Of Analog Materialsmentioning

confidence: 99%

Foamquake: A Novel Analog Model Mimicking Megathrust Seismic Cycles

et al. 2022

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“…In addition, the need for research development concerning the strength of upholstery covers is a consequence of the scarce number of publications covering fabrics in general (considered as the outer layer of upholstery systems). From the literature review, it is evident that available scientific works concern mainly the analysis of upholstery systems: springs [ 22 , 23 ] and foams [ 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 ]. Publications dealing with fabrics used in the production of upholstered furniture most often concern fire safety of housing and furniture flammability [ 36 , 37 , 38 , 39 , 40 ].…”

Section: Introductionmentioning

confidence: 99%

Study on the Influence of Selected Fabrics and Stitching on the Strength of Upholstery Covers

et al. 2022

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So far, no coherent and comprehensive method has been elaborated allowing investigation of tensile strength of upholstery seams dedicated to upholstered furniture. Producers of this type of furniture are interested in the assessment of the quality of upholstery material joints, which seems to be particularly important for ensuring the appropriate quality of products. Therefore, the objective of this research was to investigate the influence of the type of material used and the direction of the fabric cut on the strength of upholstery covers. Static tensile testing of selected upholstery fabric samples was performed, and an attempt was made to identify the most optimal fabric–seam joints. It was stated as a conclusion that the fabric tensile strength was the highest for Secret 10 fabric. In addition, the strength of upholstery covers is not influenced by the direction of the fabric die cut. For each fabric, a different configuration is preferable, as shown by results (Power 13: A-B, Secret 10: B-B, Soft 10: A-A). The method, implemented for upholstered furniture, allows for an objective assessment of the strength of upholstery covers and the selection of the most advantageous fabric–seam combination for future furniture designs.

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“…They used the basis of the non-linear Mooney-Rivlin Model to calculate the interaction mechanics between different polyurethane foams (T2516, T2838, T3530, and T4060) and human tissue. The foams were compressively tested to obtain their stress-strain graphs shown in Figure 2 With the test data, the researchers used a numerical hyperelastic polyurethane human-foam system to model developed in ABAQUS® (Dassault Systems, Waltham, MA, USA) to determine the strain of the foams [18]. They compared this numerical data to the experimental values gathered and found a strong correlation between the two sets.…”

Section: Methods For Modelling and Measuring Materials Stiffnessmentioning

confidence: 99%

Seat Backrest Morphing Using Nitinol Actuators

Jiang

2024

Preprint

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This thesis proposes a new method of seat cushion shape morphing. The proposed method is a flexible patch-based approach allowing localized morphing for areas of the back or neck that are often lack of support. The focus of this work is on the lumbar region to demonstrate cushion morphing to provide the needed support. The thesis introduces Nitinol, a shape memory alloy, and describes the process of making Nitinol springs as the actuators to bend a flexible panel behind the lumbar area for cushion morphing. An approximation theory has been developed to relate the human weight to the required stiffness for spring design and fabrication. The spring control issues have been studied to address, i) the blasting current for obtaining desired shape deformation, and ii) the holding current for maintaining deformation. Settling time and spring temperature have been studied to culminate in a final design. At last, the springs have been integrated with a cushion support panel in the lumbar area for a commercial chair. Along with a pressure sensing cover, a morphing chair backrest has been developed under a closed-loop control. It has been successfully tested that this chair can automatically adjust the lumbar profile according to an allowable sitting pressure.

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Effects of Aging of Polyurethane Foams in the Context of Furniture Design

Abstract: • An ergonomic seat or bed must be capable of supporting optimally and evenly the user's body for sustained periods of time. The objective of the performed investigations was to ascertain the impact of natural ag-

Cited by 8 publications

References 6 publications

Foamquake: A Novel Analog Model Mimicking Megathrust Seismic Cycles

Foamquake: A Novel Analog Model Mimicking Megathrust Seismic Cycles

Study on the Influence of Selected Fabrics and Stitching on the Strength of Upholstery Covers

Seat Backrest Morphing Using Nitinol Actuators

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