Research

In the dynamic landscape of structural engineering, I find my deepest interest lies in the potential of numerical modeling as a tool for transformative changes. As I navigate through the complexities of mathematics and weave them into engineering practices, I am fascinated by the diverse ways we can predict and understand the behavior of structures.

I perceive my role as a researcher to be more than just executing calculations or simulations. I am an active participant in the narrative of structural engineering evolution. I derive immense satisfaction from developing new models and incorporating complex mathematical theories, continually pushing the boundaries of what we know and can accomplish.

1. Computational Mechanics-based Constitutive Models of Cohesive Interfaces for Masonry Mortar Joints

(1) Off-the-shelf modeling techniques for the simulation of masonry walls

Highlights:

• Contact-based cohesive surfaces for mortar joints

• Material importance investigation on the IP and OOP behavior of URM walls

Publication:

Zeng, B., Li, Y., and Noguez, CC. Modeling and parameter importance investigation for simulating in-plane and out-of-plane behaviors of un-reinforced masonry walls. 2021. Engineering Structures. https://doi.org/10.1016/j.engstruct.2021.113 233 

(2) Plasticity-based multi-yield surfaces constitutive model for cohesive interfaces

Highlights:

• • Two hyperbolic yield surfaces capable of capturing various failure modes (e.g., tensile cracking, shear sliding, compressive crushing)

  • An unassociated flow rule to capture the 'dilatancy' phenomenon

  • A fully implicit Euler backward integration algorithm combined with the local-global Newton-Raphson method to guarantee the accuracy

  • An error-based auto-adaptive sub-stepping algorithm to achieve the robustness and efficiency

Publications:

• • Li, Y., and Zeng, B (Corresponding Author). Modeling of Masonry Structures Using a New 3D Cohesive Interface Material Model considering Dilatancy Softening. 2023. Engineering Structures. https://www.sciencedirect.com/science/article/pii/S0141029622015425

  • Zeng, B., and Li, Y. Advanced 3D interface model for finite element analysis of unreinforced masonry structures. 14th Canadian Masonry Symposium, Montreal, Canada. 2021

(3) Damage-plasticity-based multi-yield surfaces constitutive model for cohesive interfaces

Highlights:

• • An extension from plasticity-based framework to damage-plasticity framework

  • Consideration of stiffness degradation, stiffness recovery, and strength softening/hardening

  • A robust semi-implicit algorithm for the damage-plasticity integration problem

Publications:

• • Zeng, B., and Li, Y. Formulation, implementation, and validation of a 3D damage-plasticity-based cohesive-interface model with multi-yield surfaces for cyclic modeling of mortar joints. Journal of Structural Engineering. Under Review

  • Zeng, B., and Li, Y. A 3D damage-plasticity based cyclic model for the cohesive interface in masonry structures. 14th North American Masonry Conference, Omaha, United States. 2023. Accepted

2. Performance-based Design for Masonry Buildings

Highlights:

• Comprehensive review of experimental and numerical studies (micro- and macro-based) on the performance assessment of masonry walls/buildings 

• Discussion on both conventional unreinforced and contemporary reinforced masonry structures

• Identification of future research needs to advance performance-based design for masonry buildings

Publication:

• Zeng, B. and Li, Y. Towards Performance-Based Design of Masonry Buildings: Literature Review. Buildings. Accepted (Invited Review Paper)

3. Investigation on In-plane (IP) and Out-of-plane (OOP) Interaction Behaviors of Masonry Walls

Highlights:

• Micro modeling strategies employed for the simulation URM and RM walls (shown below)

• User-friendly python tools developed for the modeling of masonry walls

• A large numerical database for masonry walls generated with various wall configurations (a total of 252 models for unreinforced masonry walls and 336 models for reinforced masonry walls)

• Comprehensive investigation of design parameters (i.e., aspect ratio, slenderness ratio, pre-compression load, reinforcement ratio) on IP and OOP capacity interactions of masonry walls

• Analytical model proposed for IP-OOP capacity interaction curves

Publications:

• Zeng, B., and Li, Y. In-plane and out-of-plane behavior interaction analysis of unreinforced masonry walls with newly developed load capacity interactive curve. Engineering Structures. Under Review

• Zeng, B., and Li, Y. Numerical investigation of reinforced masonry walls under bi-directional loading: in-plane capacity reduction due to out-of-plane loading. Journal of Structural Engineering. Under Review

• Zeng, B., and Li, Y. Python-based Tool for Simplified and Detailed Micro Modeling of Masonry Walls Using Proprietary and Public Constitutive Models in ABAQUS. Engineering Mechanics Institute Conference 2023, Atlanta, Georgia, United States. 2023. Accepted

4. Multi-fidelity Surrogate Modeling and Uncertainty Quantification for Computationally Expensive Problems (with Applications on Masonry Walls)

(1) Multi-fidelity model-based statistical estimation through control-variate techniques

Highlights:

• Information fusion through high-fidelity (HF) FE micro model and low-fidelity (LF) design-code model (CSA S304-14) for masonry walls

• Unbiased statistics estimators constructed (superior to biased surrogate model-based estimators)

• Unbiased and efficient reliability estimators constructed

• Significant variance reduction and at least one order accuracy improvement achieved

Publications:

• • Zeng, B., and Li, Y. Uncertainty Analysis for In-plane Capacity of Un-reinforced Masonry Walls Assisted by Multi-fidelity Approach: Statistics Estimation and Global Sensitivity Analysis. CSCE Annual Conference, Moncton, Canada. 2023. Accepted

  • Zeng, B., and Li, Y. Multi-fidelity statistical estimation of IP and OOP capacity of masonry walls. To be submitted to Structural Safety

  • Zeng, B., and Li, Y. A novel efficient multi-fidelity reliability analysis framework for computationally expensive problems. To be submitted to Structural Safety

(3) Enhanced prediction and uncertainty analysis for in-plane and out-of-plane resistances of unreinforced masonry walls

Highlights:

• • • Multi-fidelity surrogate model constructed by multi-fidelity Gaussian Process

    • Enhanced deterministic and probabilistic resistance prediction for URM walls

Publications:

• • Zeng, B., and Li, Y. Enhanced resistance prediction and uncertainty analysis for in-plane and out-of-plane resistance of un-reinforced masonry walls: multi-fidelity approach. ASCE-ASME Journal of Uncertainty and Risk Analysis. Under Review

(4) Surrogate Model-based Probabilistic Analysis for Reinforced Concrete Masonry Walls under Out-of-plane Loading

Highlights:

• Surrogate model constructed to facilitate the probabilistic analysis

• Uncertainty analysis, global sensitivity analysis and reliability analysis performed by considering the model error

Publications:

• Metwally, Z., Zeng, B., and Li, Y. Probabilistic behaviour and variance-based sensitivity analysis of reinforced concrete masonry walls considering slenderness effect. 2022. ASCE-ASME Journal of Uncertainty and Risk Analysis. https://ascelibrary.org/doi/full/10.1061/AJRUA6.0001273

• Li, Y., Metwally, Z., and Zeng, B (Corresponding Author). Model error assessment of out-of-plane load capacity models for reinforced concrete masonry walls in CSA S304-14 and TMS 402-16. Journal of Structural Engineering. Under Review.

• Li, Y., Metwally, Z., and Zeng, B (Corresponding Author). Reliability evaluation of reinforced concrete masonry walls under out-of-plane loading considering slenderness Effect. Engineering Structures. Under Review