Kazuhiro Saitou, Ph.D.
Department of Mechanical Engineering
University of Michigan



Following are the research projects we have worked in the recent past, listed in alphabetical order. This simply means there is currently no student working on them. They can become active topics anytime with interested students and funding availability as we believe there are plenty of opportunitiesd for further investigation.

Assembly Synthesis for Component Modularity

The goal of this project is to develop a computational method to identify modular structural components that are sharable among multiple structures. The method simultaneously decomposes the multiple structures with given geometries such that the reduction of structural strength of each structure due to the introduction of joints, and the overall manufacturing cost are minimized. The types of welded joints at component interfaces are selected from a given library, and the manufacturing costs of components are estimated under given production volumes considering the economies of scale. A multi-objective genetic algorithm is utilized to allow effective examination of trade-offs between manufacturing cost and structural strength.


Assembly Synthesis for Robust Dimensional Integrity

The goal of this project is to develop a computational method to design an assembly and the corresponding fixture schemes and assembly sequence, such that the dimensional integrity of the assembly is insensitive to the dimensional variations of individual parts. The method recursively decomposes a given product geometry into two subassemblies until parts become manufacturable. At each recursion, joints are assigned to the interfaces between two subassemblies to ensure the in-process dimensional adjustability and proper part constraints.


Customer Driven Co-Design of Complex Products

In order to design innovative products, companies are involving customers in product design process through co-design. Co-design is changing the conventional design processes and replacing them with design processes that make customers an integral and active member of the design team. This co-operation between customers and companies has resulted in some very successful product designs. Nevertheless, co-design is still limited to very specific types of products. The research work will develop modified product design processes that are suitable for co-design and measure their success in innovative designs of complex products. This project is worked in collaboration with Prof. Richard Gonzalez in Department of Psychology.


Design for Crash Satety using Equivalent Mechanism Models

The goal of this project is to develop an efficient method for vehicle crashworthiness design based on a reduced-order model of vehicle structures, called “equivalent” mechanism (EM) model. An equivalent mechanism (EM) model is a network of rigid links with lumped masses connected by prismatic and revolute joints with nonlinear springs, which approximate aggregated behaviors of structural members during crush. An EM model of a vehicle is optimized by selecting the nonlinear springs among the ones realizable by thin-walled beams. The optimum EM model serves to identify a good crash mode (CM), the time history of collapse of the structural members, and to suggest the sizes of the structural members to attain it. After the optimization, the FE model of an entire structure is “assembled” from the suggested dimensions, which is further modified to attain the good CM identified by the optimum EM model.


Design for Disassembly with Heat Reversible Locator-Snap System

As recent legislative and social pressures drive manufacturers to consider effective part reuse and material recycling at the end of product life at the design stage, it becomes crucial to design and use joints that can disengage with minimum labor, part damage, and material contamination. This project presents a unified method to design high-stiffness reversible locator-snap system that can disengage non-destructively with localized heat. The problem is posed as an optimization problem to find the orientations, numbers, and locations of locators and snaps, and the number, locations and sizes of heating areas, which realize the release of snaps with minimum heating and maximum stiffness, while satisfying all motion and structural requirements.


DFIP: Design for IP Protection

Component outsourcing is often practiced in today’s markets in order to reduce the overall cost of products and maximized profitability. However, when new innovative products are introduced into markets, there is the concern that outsourcing would cause the product’s details to be reviled, and ‘similar’ products finding their way into the market. This research aims at developing a framework for product functionality decomposition and selective outsourcing in order to protect the key competencies and intellectual property, while satisfying quality, cost and lead-time requirements.


Design for Product-Embedded Disassembly

Design for product-embedded disassembly is a new approach to Design for Disassembly that aims at designing products with built-in disassembly means to be activated at the end of product life. the relative motions of components are constrained by the locators (tabs, slots, lips, rests, etc) integral to the components, in such a way that the removal of one or few fasteners would cause the self-disintegration of the assembly in a unique sequence, much like the domino effect.


Optimally Adaptive Product and Supply chain Systems under Severe Uncertainty

Currently, manufacturing enterprises in the high competitive global markets are vulnerable to uncertainties arising from disruptive events such as natural disasters, new technologies, or changes in environmental regulations. It is highly desirable to invest in resilience and flexibility so as to make a decision before the disruptions. The objective of the research is to enable a manufacturing enterprise to proactively adapt the product designs and the supply chains in anticipation of unplanned, but foreseeable high impact events, while still maintaining the competitive product quality, cost, and lead-time. This work is done in collaboration with Dr. Lalit Patil in Department of Mechanical Engineering.


Solar Energy Concentrators for Hydrogen Production

Solar energy is a promising sustainable source for hydrogen production for fuel-cell vehicles. In most utility-scale applications, solar energy is concentrated as heat which, through an intermediate stage can be used to generate electric power that drives an electrolyses reaction to extract hydrogen from water. Alternatively, the heat energy can be directly utilized within a thermal-catalytic cycle. Solar powered hydrogen production is beset however by challenges in investment costs, power efficiency, variability in irradiance over daily and seasonal cycles, as well as maintenance costs. This project aims to develop hierarchal optimization models for system and device-level for the solar energy concentration, dispatch and usage, with the objective of overcoming many of the cost and efficiency challenges.