Hamid Dalir

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https://hdl.handle.net/1805/26673

Lighter Composite Parts for Automotive and Aerospace Structures

While conventional carbon fiber composites are being widely used in aerospace and defense sectors, their layered nature causes interlaminar strength disadvantages leading to their premature failure under operational loading. After working for almost eight years in composites R&D for aerospace and defense and understanding the key challenges, Professor Dalir, along with Professor Mangilal Agarwal and Professor Amanda Siegel, started investigating the use of fine filaments ("'100 nm) of Carbon Nanotube/Epoxy nanocomposites developed as part of this project at INDI enabling the industry a potential 30% additional weight saving.

Manufacturing lighter but tougher structures motivated the researchers to inaugurate a university startup named "Multiscale Integrated Technology Solutions LLC" in June of 2019 where the focus has been on working with companies such as Dallara, SRAM, and Bauer to reduce the weight and cost of their parts which means less use of non-eco-friendly carbon fibers leading to lower CO2 emissions improving the quality of life of our nation. In 2021, they secured several grants and investments on their technology. They also won a statewide competition held by Indiana Elevate Nexus, which resulted in investments from the state in their technology.

They also received over $400,000.00 grants from various agencies including National Science Foundation (NSF), Indiana Economic Development Corporation (IEDC), and Elevate, among others. In addition, they have been featured in several interviews such as "Inside Indiana Business", "Tech Talk with Steve Sweitzer'', "FOX 59", and "WTHR".

They anticipate additional investments in 2022. MITS has secured the key IP from IUPUI including full rights to develop, exercise, license, sublicense, market, and sell technologies related to the material system proposed in this research.

Professor Dalir's translation of research into advanced, eco-friendly automotive and aerospace structures is another excellent example of how IUPUI's faculty members are TRANSLATING their RESEARCH INTO PRACTICE.

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Now showing 1 - 10 of 25

Symmetrical and Antisymmetrical Sequenced Fibers with Epoxy Resin on Rectangular Reinforced Structures under Axial Loading
(2018) Moheimani, Reza; Sarayloo, Reza; Dalir, Hamid; Mechanical Engineering and Energy, School of Engineering and Technology
In this study, Finite element Method (FEM) evaluation is performed for the compressive failure of reinforced structures with layered composite shells under axial loading. In addition, embedded delamination between the reinforcing layered composite shells and the core is considered as a defect. The layered composite shells are made of 12 plies of equal thickness of Kevlar, CFC, and E-Glass with epoxy resin. Considering the orientation and laminate, three different layered composite shells, (0°/90°/0°/90°/0°/90°), (45°/-45°/0°/90°/60°/-30°), and (60°/-30°/90°/0°/30°/90°), are considered for symmetrical and antisymmetrical sequences. These results are obtained through ABAQUS simulations and subsequent analysis. The results show that symmetrical and antisymmetrical sequences can be used as an index for quality control and as a safety factor of composite shells produced by the hand lay-up technique in certain industrial processes. The delamination growth is also investigated with the help of cohesive elements. Buckling phenomenon occurred abruptly due to the fast propagation of delamination, having face/core debond.
Thick-Walled Functionally Graded Material Cylinder under Thermo-Mechanical Loading
(IEEE, 2018-07) Moheimani, Reza; Nayebi, Ali; Damadam, Mohsen; Dalir, Hamid; Engineering Technology, School of Engineering and Technology
In this paper, elasto-plastic analysis of a thick-walled cylinder made of functionally graded materials (FGMs) subjected to constant internal pressure and cyclic temperature gradient loading is carried out using Matlab. The material is assumed to be isotropic and independent of temperature with constant Poisson's ratio and the material properties vary radially based on a power law volume function relation. The Von Mises' yield criterion and the Armstrong-Frederick nonlinear kinematic hardening model were implemented in this investigation. To obtain the incremental plastic strain, Return Mapping Algorithm (RMA) was used. At the end, the Bree's interaction diagram is plotted in terms of non-dimensional pressure and temperature.
Application of Laminated Composite Grids as a Reinforcing Element of Automotive Components
(ASC, 2018-09) Ehsani, Amir; Dalir, Hamid; Mechanical Engineering and Energy, School of Engineering and Technology
This paper intends to present the application of laminated grid structures as a new class of stiffeners for reinforcing body and chassis of transportation vehicles. A laminated grid plate is constituted from several grid plies with different orientations. Therefore, the grid layers with various fibers, patterns, and orientations can be used, resulting in laminates with enhanced stiffness and coupling effects. In this study, a hypothetical trunk floor is assumed as a sandwich panel with two skins and a composite laminated grid core, which is clamped along all edges. Three different grid structures are considered as the core to strengthen the trunk floor subjected to arbitrary lateral loads. Moreover, the first natural frequency of the plates are achieved. The Ritz method is employed to obtain the maximum deflection and free vibration frequencies of the trunk’s floor panel. The results indicate that employing the laminated grids considerably enhances the response of the panel in comparison with conventional grids.
Bree's diagram of a functionally graded thick-walled cylinder under thermo-mechanical loading considering nonlinear kinematic hardening
(Elsevier, 2018-09-01) Damadam, Mohsen; Moheimani, Reza; Dalir, Hamid; Mechanical and Energy Engineering, School of Engineering and Technology
In this paper, elasto-plastic analysis of a thick-walled cylinder made of functionally graded materials (FGMs) subjected to constant internal pressure and cyclic temperature gradient loading is carried out using MATLAB. The material is assumed to be isotropic and independent of temperature with constant Poisson's ratio and the material properties vary radially based on a power law volume function relation. The Von Mises’ yield criterion and the Armstrong-Frederick nonlinear kinematic hardening model were implemented in this investigation. To obtain the incremental plastic strain, return mapping algorithm (RMA) was used. At the end, the Bree's interaction diagram is plotted in terms of non-dimensional pressure and temperature which represents an engineering index for optimum design under thermo-mechanical loading.
Rapid Generation of Parametric Aircraft Structural Models
(ARC, 2019) Joe, John; Gandhi, Viraj; Dannenhoffer, John F., III; Dalir, Hamid; Mechanical and Energy Engineering, School of Engineering and Technology
Within the aerospace design, analysis and optimization community, there is an increasing demand for automatic generation of parametric feature tree (build recipe) attributed multidisciplinary models. Currently, this is mainly done by creating separate models for different disciplines such as mid-surface model for aeroelasticity, outer-mold line for aerodynamics and CFD, and built-up element model for structural analysis. Since all of these models are built independently, any changes in design parameters require updates on all the models which is inefficient, time-consuming and prone to deficiencies. Here a browser-based system, called the Engineering Sketch Pad (ESP), is used. It provides the user with the ability to interact with a configuration by building and/or modifying the design parameters and feature tree that define the configuration. ESP is based an open-source constructive solid modeler, named OpenCSM, which is built upon the OpenCASCADE geometry kernel and the EGADS geometry generation system. The use of OpenCSM as part of the AFRL’s CAPS project on Computational Aircraft Prototype Syntheses for automatic commercial and fighter jet models is demonstrated. The rapid generation of parametric aircraft structural models proposed and developed in this work will benefit the aerospace industry with coming up with efficient, fast and robust multidisciplinary design standardization of aircraft structures.
Design and Analysis of an Optimized Formula 3 Nosecone Structure
(ASC, 2019) Deshpande, Archit; Venugopal, Naveen; Dalir, Hamid; Mechanical and Energy Engineering, School of Engineering and Technology
In order to ensure the driver safety in motorsport crashes, special crash structures are designed to absorb the race car’s kinetic energy and limit the decelerations acting on the human body. The use of Carbon fibre epoxy as a primary structural material has been evident in the motorsport industry. By utilizing monolithic structure for crash, large amount of energy can be absorbed. However, the energy absorbing capacity, unlike metals, is highly dependent on the geometry, number of layups and layup orientation angles. By optimizing the plies and the orientation along the geometric cross-section, the deceleration of the vehicle can be controlled. For the FIA crash test regulations, the deceleration was limited to 5g’s for the first 150mm of crushing and the average deceleration was limited to 25g’s. By dividing the geometry into sections, the ply orientation, and number of plies were varied. This resulted in a nosecone structure weighing around 2.1 kgs, but able to meet the above requirements. From the research1 it is evident that the Specific Energy Absorption (SEA) is not only a function of geometric cross-section (φ) but also the angle of attack (β). The angles of attack were varied from 5.5° to 32.5° and the effects on SEA were observed. The dynamic simulations were conducted in explicit solver LS-DYNA using Mat_ENHANCED_COMPOSITE_DAMAGE material model (MAT54). The simulation results were validated with crush test data for energy absorbed.
Specific Energy Absorption Improvement of Rear Crash Attenuator by Numerical Modelling for Various Angles of Impact
(ASC, 2019) Venugopal, Naveen; Deshpande, Archit Milind; Dalir, Hamid; Mechanical and Energy Engineering, School of Engineering and Technology
This research* aims on developing a reliable finite element framework to investigate the Specific Energy Absorption (SEA) of the rear crash attenuator of an open-wheel type Indycar vehicle. A meshed model representing the crash structure was designed and its failure behaviour was learnt on the basis of various non-linear finite element modelling techniques to simulate a crash as per regulations from the governing body of Indycar. All the numerical analysis was performed utilizing the LS-DYNA software with the Progressive Failure Model (PFM) and Continuum Damage Model (CDM) of MAT058_LAMINATED_COMPOSITE_FABRIC card. The sandwich structure material characterization for the tuning of the material model was done by the means of a correlation with experimental data and adjusting the non-physical input parameters in the software. Post calibration, the development of the rear impact attenuator was performed with the model. A combined failure mode was observed with a gradual crushing phenomenon during the analysis on head-on impacts (0°) while in case of oblique impacts performed at 30° off axis shows the structure failing at its rear attachment points to the bulkhead. The specific energy absorption was determined at different configurations of impact of this reinforced sandwich structure by evaluating the force over a crushed displacement. The layup was adjusted, the sensitive points at the attachments were stiffened, and the core thickness was varied throughout the structure to improve the overall specific energy absorption by 27.8% with a gradual deceleration value to that of the prescribed. Finally, the results were compared to the previous Indycar structure and the rear crash attenuator was redesigned with highlights of the refreshed results.
Analysis of Spring-in for Composite Plates Using ANSYS Composite Cure Simulation
(American Society for Composites, 2019) Patil, Ameya; Moheimani, Reza; Shakhfeh, Talal; Dalir, Hamid; Mechanical and Energy Engineering, School of Engineering and Technology
Process induced dimensional changes in composite parts has been the topic of interest for many researchers. The residual stresses that develop in fiber-reinforced laminates during curing process while the laminate is confined to the process tool often leads to dimensional changes such as spring-in of angles and warpage of flat sections. Many experimental studies have put emphasis on this issue and various researches show different methods to predict these dimensional changes. The traditional trial-and-error approach can work for simple geometries, but composite parts with complex shapes require more sophisticated models. When composite laminates are subjected to thermal stresses, such as the heating and cooling processes during curing, they can become distorted as the difference between the in-plane and the through-thickness thermal expansion coefficient, as well as chemical shrinkage of the epoxy, causes the enclosed angle of curved sections and angle components to be reduced. Distorted components can cause problems during assembly, significantly increasing production costs and affecting performance. This paper focuses on predicting these shape deformations using software simulation of composite manufacturing and curing. Various factors such as resin shrinkage, degrees of cure, difference between coefficient of thermal expansion of mold and composite are taken into consideration. A cure kinetic model is presented which illustrates the matrix behavior during cure.
Influence of Employing Laminated Isogrid Configuration on Mechanical Behavior of Grid Structures
(Sage, 2019-08) Ehsani, Amir; Dalir, Hamid; Mechanical Engineering and Energy, School of Engineering and Technology
For a long time, a single grid layer, such as isogrid, have been utilized to strengthen a shell or plate or as an independent structural member for various applications. Laminated grid structures consist of several grid layers that can have different in-plane orientations or can be made from different materials. Therefore, using laminated configuration instead of conventional grids yields to an extensive variety of configurations with different coupling effects and cost. In the current paper, to evaluate the appropriateness of laminated isogrids, the vibration and stability behaviors of a conventional isogrid are compared with corresponding laminated isogrid plate. The first-order shear deformation plate theory as well as the Ritz theorem is utilized to achieve the critical buckling loads and free vibration frequencies of the plates. The influence of increasing the number of isogrid plies and changing pattern geometries on mechanical behaviors of the laminated isogrid plate is also investigated. The results imply that utilization of the laminated isogrids remarkably enhances the buckling load and free vibration frequency values of the plates.
Electrospun Nanofibers for Label-Free Sensor Applications
(MDPI, 2019-08-17) Aliheidari, Nahal; Aliahmad, Nojan; Agarwal, Mangilal; Dalir, Hamid; Engineering Technology, School of Engineering and Technology
Electrospinning is a simple, low-cost and versatile method for fabricating submicron and nano size fibers. Due to their large surface area, high aspect ratio and porous structure, electrospun nanofibers can be employed in wide range of applications. Biomedical, environmental, protective clothing and sensors are just few. The latter has attracted a great deal of attention, because for biosensor application, nanofibers have several advantages over traditional sensors, including a high surface-to-volume ratio and ease of functionalization. This review provides a short overview of several electrospun nanofibers applications, with an emphasis on biosensor applications. With respect to this area, focus is placed on label-free sensors, pertaining to both recent advances and fundamental research. Here, label-free sensor properties of sensitivity, selectivity, and detection are critically evaluated. Current challenges in this area and prospective future work is also discussed.

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