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  • Smart Green Composite

    Research field: Smart composite material and structures

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Investigation of the Effect of 3D printing parameters on shape-shifting of flat sturctures to Three-Dimensional Shapes

Maryam Jamshidi, Iman Salimi Nezhad, Mohammad Golzar, Amir Hossein Behravesh
Journal PaperJournal of Science and Technology of Composites , Volume 7 , Issue 4, 2021 February 19, {Pages 1271-1278 }

Abstract

3D printing technology is one of the new manufacturing methods that can be used to build folding structures. Folding structures are made flat and deformed into three-dimensional shapes by an actuator. FDM process is one of the most common and cheap 3D printing processes that in this study, the most effective parameters of this process were investigated. For this purpose, the optimal values of printing parameters including printing pattern, thickness of each layer, filling percentage and nozzle temperature to achieve maximum deformation (curvature) were determined by Taguchi experiment design. Then, by adjusting these parameters, the effect of printing speed and total thickness on curvature was investigated. The results showed that with incr

Modeling Bistable Behaviors in Exposure of Thermo-Viscoelastic Conditions by Link-Spring-Dashpot Structures

M Shahryarifard, Mohammad Mahdi, Golzar, G Tibert
Journal Paper , , {Pages }

Abstract

Comprehensive Study on Shape Shifting Behaviors of Thermally Activated Hinges in FDM-based 4D Printing

IS Nezhad, M Golzar, A Behravesh, S Zare
Journal Paper , , {Pages }

Abstract

3D printing of Shape-memory polymer based on Polylactic-acid and ThermoPlastic-Elastomer: Investigating of Shape-memory and Thermo-Viscoelastic properties

Amir Hasanzadeh, Mohammad Golzar
Journal PaperModares Mechanical Engineering , Volume 20 , Issue 8, 2020 July 10, {Pages 1967-1978 }

Abstract

[1] Thermally actuated shape-memory polymers: Experiments, theory, and numerical simulations [2] Recent advances in polymer shape memory [3] Smart composites of piezoelectric particles and shape memory polymers for actuation and nanopositioning [4] Computational and experimental investigation into mechanical performances of Poly-L-Lactide Acid (PLLA) coronary stents [5] Micro-vascular shape-memory polymer actuators with complex geometries obtained by laser stereo lithography [6] Shape recovery characteristics of SiC/C/PLA composite filaments and 3D printed parts [7] Processing and properties of polymer microlayered systems [8] Shape memory properties of melt-blended polylactic acid (PLA)/thermoplastic polyurethane (TPU) bio-based blends [9]

An experimental investigation on shape memory polymer and metallic stents under bending and radial compression

Mehdi Ansari, Mohammad Golzar, Mostafa Baghani, Mehrnoosh Taghavimehr, Mehran Abbasi Shirsavar, Mahsa Yahyavi
Journal PaperEngineering Research Express , Volume 2 , Issue 4, 2020 October 21, {Pages 045012 }

Abstract

In this paper, shape memory polymers (SMPs) are fabricated by blending Polyurethane (PU) and Polycaprolactone (PCL). A novel method is used to make tubular stents using this blend. The solution coating method is applied to fabricate the SMP stent samples with a non-groove structure. Some metallic commercial stents made of the platinum-chromium alloy are used to compare SMP stents' the mechanical properties with metal ones. According to the stents' functionality, two mechanical tests, i.e., radial compression and three-point bending, are conducted in a range of body temperature. According to the mechanical test results, the tubular polymer stent shows a lower strength under the radial forces and a higher strength under the bending forces tha

Toward thermal stimulation of shape memory polymer composite bistable tape springs

Mohammadmahdi Shahryarifard, Mohammad Golzar, Gunnar Tibert
Journal PaperSmart Materials and Structures , 2020 December 14, {Pages }

Abstract

Due to their tailored thermomechanical behavior and functionality, shape memory polymer matrix composites (SMPCs) are attractive as deployable structures in aerospace applications. An analytical model based on the classical laminate theory, together with the principle of minimum potential energy is developed to capture the thermo-viscoelastic behavior of a bistable tape spring (BiTS). These tape springs are known to snap between two stable configurations by different stimulus. Here, a shape memory polymer as the matrix of a fiber-reinforced polymer BiTS is introduced to actuate the snap-back. Experimental characterization was performed to obtain the time-temperature dependent properties of a Polyurethane SMPC. The time-temperature superposi

Viscoelastic bistable tape spring behavior modeled by a two-dimensional system with rigid links, springs and dashpots

Mohammadmahdi Shahryarifard, Mohammad Golzar, Gunnar Tibert
Journal PaperComposite Structures , 2020 October 29, {Pages 113181 }

Abstract

Bistable composite tape springs are often used as deployable structures in aerospace applications because of their ability to be tailored for compact size, deployed lengths and stiffness. Analytical studies of the coupling between stress-strain and moment-curvature of thin curved shells have been used to estimate the total stored strain energy in different tape spring configurations. The strain energy as function of the curvatures reveals the fundamental stability behavior of the tape springs in the different configurations. The present study investigates the minimum strain energy path between two stable equilibrium points and the passage through the unstable saddle point along this path. For a coiled fiber-reinforced composite tape spring,

Ultrasonic welding of thermoset matrix composites reinforced with glass fibers using a co-cured retaining layer

A JabariRad, D Akbari, M Golzar
Journal PaperJournal of Welding Science and Technology of Iran , Volume 6 , Issue 2, 2020 December 10, {Pages 137-144 }

Abstract

In this paper, ultrasonic welding of glass fiber reinforced thermoses, co-cured whit a thermoplastic has been studied. Co-curing process forms a connection between the thermoset and the thermoplastic while curing the composite. Considering that the calculated stress should not be related to the dimensions of the sample, a horn with a tip dimension smaller than the standard overlap was used. The results show that the actual weld dimensions are bigger than the intended weld dimensions. This has happened due to the movement of the melted thermoplastic to the sideways during the welding. The design of experiment has been done using response surface central composite, and a quadratic equation based on the lap shear strength of the welds containi

Fabrication and evaluation of print quality of Polylactic acid cylindrical scaffolds as stents and the effect of geometry on their shape memory properties

S Zare, M Golzar, M Ansari
Journal Paper , 2020 January , {Pages }

Abstract

Original Research Memory-shaped polymers are thermally induced subsets of intelligent materials that require thermomechanical behavior to accurately understand their function. In this study, polymeric memory scaffolds were fabricated using polylactic acid by molten labeling method in reticular honeycomb, rhombic and elliptical forms. Parameters such as longitudinal dimensions and the wall thickness of printed scaffolds compared to the designed scaffolds and solutions were presented to enhance the printing accuracy. Built-in scaffolds can be a good option for stent use. Formal memory properties experiments with 30% axial strain were performed to study the shape memory behavior of polymer on scaffolds. The results showed that the percentage o

An experimental–numerical study on shape memory behavior of PU/PCL/ZnO ternary blend

M Abbasi-Shirsavar, M Baghani, M Taghavimehr, M Golzar, M Nikzad, M Ansari, D George
Journal PaperJournal of Intelligent Material Systems and Structures , Volume 30 , Issue 1, 2019 January , {Pages 116-126 }

Abstract

Shape memory polymer composites have attracted significant attention due to novel properties and great applications. In this article, we focus on the fabrication and simulation of polyurethane/polycaprolactone nanocomposites. The polyurethane/polycaprolactone blends containing ZnO nanoparticles (5 to 30 wt%) are fabricated using a solution mixing and casting method. It is found that significant improvement of polyurethane/polycaprolactone composites in Young’s modulus is achieved by incorporating 20 wt% of ZnO nanoparticles; also, the results of the shape recovery ratio reveal that adding an optimum amount of ZnO (the reinforcement) can increase the shape recovery ratio (for 20 wt% of ZnO). These results could most likely be explained by

Force recovery evaluation of thermo-induced shape-memory polymer stent: Material, process and thermo-viscoelastic characterization

Mehdi Ansari, Mohammad Golzar, Mostafa Baghani, Mehran Abbasi Shirsavar, Mehrnoosh Taghavimehr
Journal PaperSmart Materials and Structures , 2019 June 11, {Pages }

Abstract

Due to their functional and biological benefits, shape memory polymer (SMP) stents have attracted the attention of researchers in the biomedical science area. The highlights of this article are the evaluation of stent performance including radial force recovery and recovery start temperature (RST) in a constrained state. The effects of polyurethane (PU) mechanical properties and fabrication method are investigated on thermo-viscoelastic properties, sample defect and shape recovery of PU and polycaprolactone (PCL) blend. Thereafter, three tubular stents fabricated with the different diameter to thickness (d/t) ratio and their mechanical behavior are examined in loading, relaxation, and unloading. Finally, the radial force recovery of the ste

Assessment of failure toughening mechanisms in continuous glass fiber thermoplastic laminates subjected to cyclic loading

Mehdi Nikforooz, John Montesano, Mohammad Golzar, Mahmood Mehrdad Shokrieh
Journal PaperComposites Part B: Engineering , Volume 161 , 2019 March 15, {Pages 344-356 }

Abstract

Tensile fatigue behaviour of glass fiber/polyamide composites, including unidirectional ([0]8, [90]8) and cross-ply ([02/902]s, [04/904]s and [904/04]s) laminates, was studied and compared to that of similar glass fiber/epoxy composites. The fatigue resistance of cross-ply glass/polyamide was greater than that of glass/epoxy while also exhibiting lower stiffness reduction. To explain this key observation, residual stiffness and residual strength fatigue tests were performed on cross-ply laminates, while optical microscopy was used to measure ply crack density during the different stages of cycling. Testing of the cross-ply laminates at lower peak stresses of 50% of the ultimate tensile strength (i.e., high cycle fatigue regime) revealed par

Experimental evaluation of joint strength in polypropylene-glass fiber reinforced composites under tensile load

MOHAMMAD NAJAFI, MOHAMMAD GOLZAR, Mohammad Sadeghi
Journal Paper , Volume 6 , Issue 200869, 2019 January 1, {Pages 39-46 }

Abstract

Thermoplastic composites are widely used in various industries due to its inherent properties. One of the most important parameters in the composite industry is the junction of composite components. In this research, the strength of joints of thermoplastic composites has been investigated empirically. Composite specimens are made of Commingled fibers which consist of glass/polypropylene, using a pultrusion process and as rectangular cross section profiles. For junction of the samples three methods are used including, bolted joint, ultrasonic weld and hot press. Based on the experimental results, the mechanical performance and failure of the ultrasonic weld and hot press methods were compared with the mechanical couplers. The results show th

A Model for Urban Development Based on Natural Infrastructure

Ali Reza Arsiya, Mohammad Reza Mehrabani Golzar
Journal Paper , 2018 January 1, {Pages }

Abstract

An effective factor in reducing the problems of modern cities is to use, regenerate and enhance green infrastructure to tackle the increasing problems of cities. From the one hand, the green infrastructure significantly influences the surrounding environment. On the other hand, the increase of the value added to the lands in the areas covered by these green elements can enrich the environmental quality in addition to improving all aspects of life. This study aims at investigating the effect of Isfahan Madis, as green infrastructures of Isfahan city, on the increase of value added to the adjacent lands. Moreover, the impact of Madis on improving the quality of life, as well as Madis patterns in promoting less developed regions are put into f

Assessment of the thermomechanical performance of continuous glass fiber-reinforced thermoplastic laminates

M Nikforooz, J Montesano, M Golzar, MM Shokrieh
Journal PaperPolymer Testing , Volume 67 , 2018 May 1, {Pages 457-467 }

Abstract

The effects of temperature on the static tensile behavior of continuous E-glass/polyamide laminates were studied in order to assess the feasibility of using the material system for structural applications. Uniaxial tensile tests were conducted on [0]8, [90]8, [02/902]s and [04/904]s laminates at multiple temperatures above and below the glass transition temperature, which was measured using different methods. Optical and scanning electron microscopy were performed on the tested samples, and the effects of temperature on failure modes were investigated. The [0]8 and [90]8 laminates displayed three reduction stages in modulus versus temperature, where the largest reduction was in the glass transition region as a result of notable softening of

Processability and tensile performance of continuous glass fiber/polyamide laminates for structural load-bearing applications

M Nikforooz, M Golzar, MM Shokrieh, J Montesano
Journal PaperComposites Part A: Applied Science and Manufacturing , Volume 105 , 2018 February 1, {Pages 156-164 }

Abstract

The performance of continuous E-glass/polyamide 6 laminates processed using distinct hot press moulding cycles was assessed and compared with similar E-glass/epoxy and E-glass/polypropylene laminates. The effects of peak processing temperature, preheating time, and temperature dwell time on laminate consolidation and quality were observed using optical and scanning electron microscopy. Corresponding quasi-static tensile tests were performed on [0]8, [90]8, [02/902]s, [04/904]s and [?45]2s laminates. Compared to E-glass/epoxy composites, the [0]8 specimens presented a similar strength, while the [90]8 specimens exhibited a much lower strength due to weaker fiber/matrix adhesion. Conversely, the E-glass/polyamide cross-ply laminates had a mar

Composites based on HDPE, jute fiber, wood, and thermoplastic starch in tubular pultrusion die: The correlation between mechanical performance and microstructure

Hamed Hedayati Velis, Mohammad Golzar, Omid Yousefzade
Journal PaperAdvances in Polymer Technology , 2018 January , {Pages }

Abstract

This paper presents an experimental study on pultrusion of tube‐shaped composites. Green tube‐shaped composites based on jute/thermoplastic starch, jute/HDPE, and jute/HDPE/wood flour were prepared. Jute fibers were impregnated in thermoplastic extrusion process, and a round prepreg was produced in a hot die. The impregnated jute fibers were entered into pultrusion die, and tube‐shaped composites were fabricated. Properties of final samples were investigated by tensile measurement and void faction. It was found that tensile strength of jute/HDPE was higher than jute/starch. It seems that the melt viscosity of polymer plays as an important role determining the mechanical performances. In addition, tensile strength increases with incre

Novel parameters in load capacity and failure of coaxial steel tubes jointed by wrapped GFRP sleeve

MM Shahryarifard, M Golzar, M Safarabadi
Journal PaperInternational Journal of Adhesion and Adhesives , Volume 82 , 2018 April 1, {Pages 79-89 }

Abstract

In this paper, the uniaxial load capacity of two coaxial steel tubes joined by glass fiber reinforced plastic (GFRP) was investigated. The axial connection was made by hoop winding of textile woven fabrics on circular hollow steel tubes. A simple efficient theory was selected to estimate the load capacity of sleeve joint. To define novel parameters in load capacity and failure, tensile tests were conducted on several specimens. Based on fracture mechanics experimental observations showed that three kinds of failure modes occurred including GFRP rupture, adhesive failure and mixed mode. The wetted cross-ply textile of woven glass was used in order to study the effect of the number of plies. One novel parameter named lamination cohesion rate

VISUALIZATION OF FLOW AND VOID IN PULTRUSION PROCESS OF THERMOPLASTIC COMPOSITES

AMIR HOSSEIN DADOU, MOHAMMAD GOLZAR, DAVOOD AKBARI, MOHAMMAD HOSSEIN MOHAMADIPOUR
Journal Paper , Volume 4 , Issue 40075, 2018 January 1, {Pages 453-463 }

Abstract

Pultrusion is a continuous method for producing profiles with a constant cross section. Because mechanical properties of pultruded composite are related to process parameters, developing a method for flow visualization is essential. In this study pultrusion of thermoplastic polymers was visualized and useful data about polymer flow and void formation during process was obtained. In this regard a straight (converging-parallel) pultrusion die with glass walls has been used for direct observation of process during pultrusion. Glass die has been heated using IR radiation for continuous heat supply and providing enough space to install visualization equipment. Also colored pellets and fibers were used for better visualization. Average velocity o

Fatigue behavior of laminated glass fiber reinforced polyamide

Mehdi Nikforooz, John Montesano, Mohammad Golzar, Mahmood Mehrdad Shokrieh
Journal PaperProcedia engineering , Volume 213 , 2018 December 31, {Pages 816-823 }

Abstract

The fatigue performance of laminated glass fiber reinforced polyamide composites was investigated in this study. Fatigue tests were conducted on both unidirectional and cross-ply specimens at room temperature. The SN diagram of [0] 8 followed a bilinear curve, however, the [90] 8 laminates presented a linear SN diagram. Compared to the same lamination of glass/epoxy,[0] 8 and [90] 8 glass/polyamide laminates presented a lower fatigue resistance, while [0 2/90 2] s laminates exhibited a superior fatigue resistance. In addition, stiffness degradation was investigated for the laminates and was compared with that of glass/epoxy with the same lamination. Glass/polyamide composites had lower stiffness reduction compared to glass/epoxy.

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