Yiding Liu

University of Hertfordshire | UH · School of Physics Engineering and Computer Scince

The theory of dynamic three-point bending under high-loading rates, up to about 70 m/s (with flexural wave dominating the global response), is developed for the first time with account for structural vibration. Analytical solutions for the dynamic normal (flexural) and shear (interlaminar) stresses are derived. To study the dynamic effect, the dyna...

Structural health monitoring (SHM) is a means for maintaining structural integrity, safety and reliability by analysing various structural responses (i.e., mechanical signals) to pinpoint the anomalies of the structures due to damage. It is not an easy task to filter the noise and fluctuation of mechanical signals to successful find the damage-indu...

Citation: Bianchi, F.; Liu, Y.; Joesbury, A.M.; Ayre, D.; Zhang, X. A Finite Element Model for Predicting the Static Strength of a Composite Hybrid Joint with Reinforcement Pins. Materials 2023, 16, 3297. Abstract: This paper presents a finite element model for predicting the performance and failure behaviour of a hybrid joint assembling fibrous co...

Adhesively bonded joints have been extensively employed in the aeronautical and automotive industries to join thin-layer materials for developing lightweight components. To strengthen the structural integrity of joints, it is critical to estimate and improve joint failure loads effectually. To accomplish the aforementioned purpose, this paper prese...

In this paper, consolidation monitoring and structural health monitoring (SHM) of a braided thermoplastic composite beam was performed using a distributed optical fibre sensor (DOFS). The DOFS was manually embedded into the braided preform before melt processing. The real-time strain and temperature data obtained during consolidation and cooling se...

The double cantilever beam (DCB) tests are widely used to assess the interfacial delamination properties of laminated composites. For quasi-static loads, the DCB tests are standardized based on the beam mechanics; for dynamic loads, however, such as high-loading-rate impact and cyclic loads, there is no established analytical theory. This presents...

This paper proposed an Acoustic Emission (AE) based Smart Composite Fastener (SCF) concept for health monitoring of bonded/bolted composite single lap joints. The SCF was made of 3D-printed continuous carbon fibre reinforced thermoplastic materials with an embedded piezoelectric sensor. The SCF detected signals were found to be successfully associa...

Braided composites have seen substantial industrial uptake for structural applications in the past decade. The dependence of their properties on braid angle provides opportunities for lightweighting through structure-specific optimisation. This paper presents an integrated approach, combining finite element (FE) simulations and a genetic algorithm...

This study presents findings for the strength and failure mechanism of a 3D-printed Continuous Carbon Fibre reinforced Onyx (CCF/Onyx) Thermo-Plastic Composite Fastener (TPCF) and a single lap-joint (SLJ) made of fibre/polymer composite reinforced by the TPCF. The study was carried out by numerical analysis and experiment methods including test sam...

To meet the high demand for lightweight energy-efficient and safe structures for transport applications, a current state-of-the-art light rail vehicle structure is under development that adopts a multi-material design strategy. This strategy creates the need for advanced multi-material joining technologies. The compatibility of the adhesive with a...

The aerospace, automotive and marine industries have witnessed a rapid increase of using adhesive bonded joints due to their advantages in joining dissimilar and/or new engineering materials. Joint strength is the key property in evaluating the capability of the adhesive joint. In this paper, developments of black-box and grey-box machine learning...

Adhesive bonded joints are one of important joining technologies in supporting various manufacturing applications. It is important to predict the optimal strength of adhesive bonded joints in order to fit design requirements. Prediction on joint strengths is usually based on experimental tests and Finite Element Analysis (FEA). However, it is a tim...

In this work, the effect of hot-humid environment on the mode II fracture energy (G IIc) of the selected structural adhesive was experimentally evaluated through End-Notched Flexure (ENF) testing as well as corresponding finite element (FE) modelling approach. The ready-cured ENF samples were first immersed in distilled water and 5% NaCl solution u...

Adhesively bonding has been increasingly used for numerous industrial applications to meet the high demand for lightweight and safer structures. Debonding of adhesively bonded joints is a typical mixed mode failure process. It is highly depended on the interactional effects of material properties and geometric definitions of the constituents, which...

Nowadays, the adhesive bonding method has a very strong presence in the most varied industries, especially in aeronautics, which strongly boosted the use of adhesively bonded joints. Curved bonded joints are commonly used in the aeronautical industry, where curved panels typically made of carbon fibre-reinforced polymer (CFRP) are joined to fabrica...

With the advancing trend towards lighter and faster rail transport, there is an increasing interest in integrating composite and advanced multifunctional materials in order to infuse smart sensing and monitoring, energy harvesting and wireless capabilities within the otherwise purely mechanical rail structures and the infrastructure. This paper pre...

This paper presents an experimental and numerical investigation in the static strength enhancement of composite laminate Single Lap bonded Joints (SLJ), reinforced by pins made of Uni-Directional (UD) fibre reinforced plastic composite materials. Bonded lap joint specimens were experimentally tested in tension to obtain the failure loads and failur...

Laboratory coupon joints for fatigue debonding tests usually have narrow width and a through-width initial disbond. However, realistic structural joints are much wider and may contain process-induced defects and accidental damage; both are much smaller than the joint width. Small and discrete damage may behave differently from the idealised through...

In this paper, the fracture responses of single lap joints of various size scales containing either a strip or semi-circular defect is presented. The study was conducted numerically by calculating and correlating the crack front strain energy release rate (SERR), which is the driving force for disbond crack propagation. Firstly, an empirical equati...

In this paper, the fracture responses of single lap joints of various size scales containing either a strip or semi-circular defect is presented. The study was conducted numerically by calculating and correlating the crack front strain energy release rate (SERR), which is the driving force for disbond crack propagation. Firstly, an empirical equati...

Curved adhesive joints are seldom studied in the literature. In the aeronautical industry, curved joints can be used to join several fuselage parts. This work aims to make a numerical evaluation of curved composite adhesive joints by cohesive zone modelling (CZM). Several geometric parameters are varied to assess their influence on the joints' beha...

This presentation talks about experimental and numerical study on the static and fatigue behaviour of wide single lap joint with process-induced semi-circular defect. Static tests were performed with laser extensometer and the joint strength was found to reduce approximately 20% by comparing to an equivalent specimen without any pre-existing defect...

This paper presents a method for predicting fatigue crack propagation in single lap adhesive bonded composite joints with an initial full-width disbond using finite element analysis and numerical integration of the material’s fatigue crack growth rate law. Fatigue tests were conducted on single lap joints to monitor crack lengths from four runout c...

The effects of size, curvature and free edges of laboratory joints representing the fracture behaviour of realistic composite fuselage structures are presented. Cohesive Zone Models (CZM) have been used to predict the strength of adhesive joints, as an add-in to Finite Element (FE) analyses that allows simulation of damage initiation process. The V...