Concrete is a widely used product and is an important application throughout industry due to its inexpensive cost and wide range of applications. This work focuses on understanding the behavior of high strength concrete in high strain rate ballistic impact loading scenarios. A finite element analysis was created with the implementation of the Concrete Damage and Plasticity Model 2 (CDPM2) to represent the material behavior. The model’s parameters were calibrated to existing literature and the results were analyzed by a comparison of the impact velocity to residual velocity and a qualitative assessment of the impact crater. The model captured the impact dynamics of the contact between the projectile and the concrete target with defined fracture patterns. Impact velocity and target thickness indicated a relatively linear relationship with the final projectile velocity.

No description available.

Brainstorming is a critical part of the engineering design process and can have a significant impact on the outcomes of the overall project. While research has studied the outcomes of brainstorming and the ideas that teams generate, the role that language and conversation play in these activities is still relatively underexplored. Observing the different ways people use specific types of discourse can reveal how conversations can affect brainstorming itself. To that end, this research aims to answer the following questions: 1) What are the different kinds of discursive moves that students make during engineering brainstorming activities? 2) What patterns or themes emerge among these discursive moves? We collected data by recording conversations that took place during team brainstorming activities with engineering students. These conversations were transcribed, and we used discourse analysis to code our data according to the speaker's intent. We combined quantitative and qualitative analysis to identify and explore correlation patterns within these conversations. Three prominent themes emerged from our analyses: Active Engagement, Group Rapport, and Exploring the Problem. These themes highlight the range of different conversational elements that work together to support effective brainstorming discussions. Engineers and engineering educators can be mindful of the way that they frame their brainstorming activities so that the team’s discourse encourages more active engagement, stronger group rapport, and deeper exploration of the problem at hand.

Master of Engineering (ME)

No description available.

The goal of this thesis is to enable a robot to actively collaborate with a person to move an object in an efficient, smooth and robust manner. For a robot to actively assist a person it is key that the robot recognizes the actions or phases of a collaborative tasks. This requires the robot to have the ability to estimate a person’s movement intent. A hurdle in collaboratively moving an object is determining whether the partner is trying to rotate or translate the object (the rotation versus translation problem). In this thesis, Hidden Markov Models (HMM) are used to recognize human intent of rotation or translation in real-time. Based on this recognition, an appropriate impedance control mode is selected to assist the person. The approach is tested on a seven degree-of-freedom industrial robot, KUKA LBR iiwa 14 R820, working with a human partner during manipulation tasks. Results show the HMMs can estimate human intent with accuracy of 87.5% by using only haptic data recorded from the robot. Integrated with impedance control, the robot is able to collaborate smoothly and efficiently with a person during the manipulation tasks. The HMMs are compared with a switching function based approach that uses interaction force magnitudes to recognize rotation versus translation. The results show that HMMs can predict correctly when fast rotation or slow translation is desired, whereas the switching function based on force magnitudes performs poorly.

Successful competition in the computer systems industry depends on a firm's ability to bring profitable products to market. The success of a product is measured by its future worth to the company. Life-cycle complete design attempts to engineer products that provide maximum future worth. Many components contribute to the overall cost of developing a product. Designing merely to reduce the cost of the components that make up the system is insufficient. A product must be engineered in a manner that addresses all pertinent issues over its complete life cycle. This research examines the use of the VHSIC Hardware Description Language as a computer-aided engineering tool for life-cycle complete engineering. VHDL is traditionally used to model the functional behavior of digital systems. This thesis provides an overview of a life-cycle complete design process and describes the use of VHDL to support that process. A case study is presented to illustrate the use of VHDL for life-cycle complete modeling. / Master of Science

In order to present technological advances (both old and new) to a wider variety of engineers, new methods such as Computer Aided Engineering (CAE) must be adopted. By defining the requirements, design, and implementation of such an environment, the design and product development cycle can be both improved and reduced. The ability to upgrade existing software tools as well as include new tools should be examined. This thesis presents the design of a general purpose CAE environment for motor drive systems. The development of a CAE package for Switched Reluctance Motor (SRM) drive systems is used to illustrate the method. Two existing software packages are modified for inclusion, and the development of a new module for the dynamic analysis of the entire drive system is presented. / Master of Science

Construction has multiple material handling equipment that cross each others’ paths. These equipments have significant dynamic behavior under various load conditions. A system to model multi-tasking material handling with dynamic behavior capabilities will provide advances in automation. Current computer graphics and CAD technology, combined with advanced engineering concepts provide the capability for a dynamic behavior modeler which is capable of modeling the dynamics of mechanisms involved in the material handling operations in construction realistically. This thesis presents a conceptual dynamic behavior modeler. The conceptual modeler is envisioned for future inclusion into a multi-tasking motion planning system for material handling in construction. The conceptual modeler is intended to perform dynamic simulation of 3-D rigid bodies for computer animation. In addition, the modeler provides a capability to model and predict real-life behavior of physical objects subject to dynamic loading. This thesis also presents a sample animation case involving a mobile crane in a "pick and place task”. Although traditional animation methods have been employed for the sample case, the animation provides an insight to the realistic visualization that would be achieved through dynamic simulation. In order to achieve a real-time animation, no finite element modeler has been utilized. Also, significant work was done to study approximation Strategies in the development of the analytical model of the sample case to improve the efficiency of the animation. The dynamic behavior modeler presented in this thesis will provide a novel approach to model the motion planning process. The modeler will ensure realistic visualization of material handling operations. The modeler will allow engineers to animate the material handling process based on dynamic simulation. Engineers will be able to realistically model critical rigging operations. The technology provided by the dynamic behavior modeler will enable engineers to better plan, model, and control the material handling process. This will further lead to significant improvements in constructability and overall performance of construction projects. / Master of Science

The internal combustion engine is synonyms with the automobile since its invention in late 19th century. The internal combustion engine today is far more advanced and efficient compared to its early predecessors. An intense competition exists today amongst the automotive OEMs in various countries and regions for stepping up sales and increasing market share. The pressure on automotive OEMs to reduce fuel consumption and emission is enormous which has lead to innovations of many variations in engine and engine-related technologies. However, IC engines are in existence for well more than a century and hence have already evolved to a highly refined state. Changes in IC engine are therefore largely incremental in nature. A deterrent towards development of an engine configuration that is significantly different from its predecessor is the phenomenal cost involved in prototyping. Thus, the only viable alternative in exploring new engine concepts and even optimizing designs currently in operation is through extensive use of CAE. In light of published work in the field of analysis of IC engines, current research effort is directed towards development of a rational methodology for arriving at a weight-optimized engine design, which simultaneously meets performance of various attributes such as thermal, durability, vehicle dynamics and NVH. This is in contrast to the current methodology adopted in industry, according to which separate teams work on aspects of engine design such as combustion, NVH (Noise, Vibration and Harshness), acoustics, dynamics, heat transfer and durability. Because of the involvement of heterogeneous product development groups, optimization of an engine for weight, which can have a significant impact on its power-to-weight ratio, becomes a slow process beset with manual interventions and compromise solutions. Thus, following the traditional approach, it is quite difficult to claim that an unambiguous weight-optimized design has been achieved. As a departure from the practiced approach, the present research effort is directed at the deployment of a single multi-physics explicit analysis solver, viz. LS-DYNA - generally known for its contact-impact analysis capabilities, for simultaneously evaluating a given engine design for heat transfer, mechanical and thermal loading, and vibration. It may be mentioned that only combustion analysis is carried out in an uncoupled manner, using proven phenomenological thermodynamic relations, to initially arrive at mechanical and thermal loading/boundary conditions for the coupled thermo-mechanical analysis. The proposed methodology can thus be termed as a semi-integrated technique and its efficacy is established with the case study of designing a single cylinder air-cooled diesel engine from scratch and its optimization.