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The interaction between hydraulic fracture (HF) and natural fracture (NF) in naturally fractured rocks is critical for hydraulic fracturing. This paper aims to focus on investigating the development of tensile and shear debonding zone on the NF caused by the stresses produced by HF, and the influence of NF’s debonding behavior on the interaction between HF and NF.

Theoretically, tensile and shear debonding modes of NF are considered, two dimensionless parameters are proposed to characterize the difficulty of tensile and shear failure of NF, respectively. Numerically, a finite element model combining the extended finite element method and cohesive zone method (CZM) is proposed to study NF’s debonding behavior and its influence on the interaction between HF and NF.

Both theoretical analysis and numerical simulation show the existence of two debonding modes. The numerical results also show that the HF can cross, offset or propagate along the NFs depending on the parameters’ value, resulting in different fracture network and stimulated reservoir volume. When they are large, the NF’s debonding area is small, HF tends to cross the NF and the fracture network is simple; when they are small, the NF’s debonding area is large, HF will propagate along the NF. In addition, HF is easier to propagate along with NF under tensile debonding mode while it is easier to pass through NF under shear debonding mode.

The theoretical and numerical considerations are taken into account in the influence of the debonding of NFs on the interaction between HFs and NFs and the influence on the formation of the fracture network.

This study aims to develop an adaptive finite element method for structural eigenproblems of cracked Euler–Bernoulli beams via the superconvergent patch recovery displacement technique. This research comprises the numerical algorithm and experimental results for free vibration problems (forward eigenproblems) and damage detection problems (inverse eigenproblems).

The weakened properties analogy is used to describe cracks in this model. The adaptive strategy proposed in this paper provides accurate, efficient and reliable eigensolutions of frequency and mode (i.e. eigenpairs as eigenvalue and eigenfunction) for Euler–Bernoulli beams with multiple cracks. Based on the frequency measurement method for damage detection, using the difference between the actual and computed frequencies of cracked beams, the inverse eigenproblems are solved iteratively for identifying the residuals of locations and sizes of the cracks by the Newton–Raphson iteration technique. In the crack detection, the estimated residuals are added to obtain reliable results, which is an iteration process that will be expedited by more accurate frequency solutions based on the proposed method for free vibration problems.

Numerical results are presented for free vibration problems and damage detection problems of representative non-uniform and geometrically stepped Euler–Bernoulli beams with multiple cracks to demonstrate the effectiveness, efficiency, accuracy and reliability of the proposed method.

The proposed combination of methodologies described in the paper leads to a very powerful approach for free vibration and damage detection of beams with cracks, introducing the mesh refinement, that can be extended to deal with the damage detection of frame structures.

The purpose of this paper is to calculate the Hugoniot relations of polyurea; also to investigate the atomic-scale energy change, the related chain conformation evolution and the hydrogen bond dissociation of polyurea under high-speed shock.

The atomic-scale simulations are achieved by molecular dynamics (MD). Both non-equilibrium MD and multi-scale shock technique are used to simulate the high-speed shock. The energy dissipation is theoretically derived by the thermodynamic and the Hugoniot relations. The distributions of bond length, angle and dihedral angle are used to characterize the chain conformation evolution. The hydrogen bonds are determined by a geometrical criterion.

The Hugoniot relations calculated are in good agreement with the experimental data. It is found that under the same impact pressure, polyurea with lower hard segment content has higher energy dissipation during the shock-release process. The primary energy dissipation way is the heat dissipation caused by the increase of kinetic energy. Unlike tensile simulation, the molecular potential increment is mainly divided into the increments of the bond energy, angle energy and dihedral angle energy under shock loading and is mostly stored in the soft segments. The hydrogen bond potential increment only accounts for about 1% of the internal energy increment under high-speed shock.

The simulation results are meaningful for understanding and evaluating the energy dissipation mechanism of polyurea under shock loading, and could provide a reference for material design.

The purpose of this paper is to develop a numerical method to model the simultaneous propagation of multiple hydraulic fractures (HFs) with fluid lags driven from a horizontal wellbore.

Fracture propagation in solid medium is modeled with the extended finite element method and fluid flow is modeled with finite volume method. Three iteration loops are introduced to solve the nonlinear system within each time increment, i.e. a Newtonian iteration to solve the solid-fluid coupling system, a Picard iteration to determine fluid front positions and a secant iteration to update fracture lengths.

The propagation of one single HF with a fluid lag is simulated and agrees well with semi-analytical solutions or other numerical results in the literature. The simultaneous propagation of two HFs are then investigated, which demonstrates the ability of the proposed method in capturing the hydraulic fracturing process with multiple fractures and fluid lags.

With the proposed method, one can simulate the simultaneous propagation of multiple HFs with fluid lags, which play a significant role during early-time propagation or when the confinement stress is relatively low (shallow HFs). Solid deformation and fracturing, fluid flow in fractures and in the wellbore are fully coupled, and three iteration loops are introduced to solve the nonlinear system.

This paper aims to propose a design method for attenuating stress waves pressure using soft matrix embedded with particles.

Based on the phononic crystal theory, the particle composed of hard core and soft coating can form a spring oscillator structure. When the frequency of the wave is close to the resonance frequency of the spring oscillator, it can cause the resonance of the particle and absorb a lot of energy. In this paper, the resonant phononic crystal with three phases, namely, matrix, particle core and coating, is computationally designed to effectively mitigate the stress wave with aperiodic waveform.

The relationship between the center frequency and width of the bandgap and the geometric and physical parameters of particle core are discussed in detail, and the trend of influence is analyzed and explained by a spring oscillator model. Increasing the radius of hard core could effectively enhance the bandgap width, thus enhancing the effect of stress wave attenuation. In addition, it is found that when the wave is in the bandgap, adding viscosity into the matrix will not further enhance the stress attenuation effect, but will make the stress attenuation effect of the material worse because of the competition between viscous dissipation mechanism and resonance mechanism.

This study will provide a reference for the design of stress wave protection materials with general stress waves.

This study proposes a design method for attenuating stress waves pressure using soft matrix embedded with particles.

The purpose of this paper is to deconstruct a growing area in marketing theory. It aims to critically examine the principles of relationship marketing as found in the literature and suggest opportunities for future conceptual maturation.

The conceptual discussion aims to assist future progress of relationship marketing and, more generally, marketing theory. While focusing on specific areas of departures and inadequacies in past and current research in the area, the discussion notes seminal philosophical questions which underpin current marketing sensibilities and which inform the nature of relational discourses.

It is argued that, in spite of recent developments in and maturation of relational discourses, some research in the field remains rather non‐contingent, theoretical and not observation‐informed. Importantly, it is biased towards the discussion of positive aspects of relationships. Matters of consequence to practice and research such as power and disciplining remain under‐researched.

By deconstructing and reconstructing current relationship marketing theory – partly by using a study of power and disciplining in situations of consumer dissatisfaction – ways of confronting shortcomings of relational research are illustrated. A more balanced and nuanced approach to marketing research and practice is proposed.

This is one of the few papers in marketing research, and relationship‐marketing research in particular, conceptually intrigued by the peculiarities of current thinking of relationships and exchanges. The contribution centres on three observations and a number of suggestions for future relational analysis. The discussion aims to help promote a fuller, deeper understanding of exchanges. It has been designed as a sketchy guide to future relationship marketing research.

This study aims to examine newcomers experiencing maladjustment due to cognitive diversity, specifically, how maladjustment affects their turnover intentions; the mediating role of reported workplace bullying; and the buffering effect of perceived inclusive practices in the hospitality sector.

The authors collected time-lagged data from 403 respondents and analyzed the data through hierarchical regression analyses using statistical package for the social sciences (SPSS) 25.0.

Role ambiguity, low self-efficacy and social exclusion could each lead to newcomers’ reported workplace bullying (NRB). Perceived inclusive practices buffered the impacts of role ambiguity and social exclusion. NRB negatively mediated the relationships between role ambiguity and NRB; and social exclusion and NRB.

Hospitality practitioners should specify work procedures to minimize role ambiguities and record service processes to correct mistakes, reward veterans who help newcomers improve self-efficacy, invite newcomers to develop inclusive practices and review employee comments on third-party platforms to understand factors responsible for turnover intention.

This study contextualized cognitive diversity into newcomers’ maladjustment-bullying-turnover model in China’s hospitality industry. It highlighted the buffering effect of perceived inclusive practices in the relationships between maladjustment and reported bullying and turnover intentions among newcomers and confirmed the important role of self-efficacy in addressing adverse work events.

The purpose of this paper is to establish manufactured construction as a good potential alternative to meet the growing housing needs of China.

The paper uses literature review and case study as research methodologies. Literature review is used to identify the need for housing and establish the manufacturing prowess of China. The case study is used to look at how a similar problem has been tackled in the UK and then the case study findings are used to identify future direction for China.

Findings suggest that there is an acute shortage of housing in China, and at the same time the manufacturing sector in China is very strong. Therefore, in order to meet the housing demand for the population, manufactured construction offers a very attractive and cost‐efficient alternative.

Manufactured construction is an attractive alternative for China and therefore the government needs to encourage this sector through subsidies and tax benefits. Given that currently China is regarded as a manufacturing powerhouse, it will be relatively easy to establish manufactured construction as an organised and supported sector by the government.

The paper presents manufactured construction as an attractive alternative and strategic direction that China should adopt to meet the growing housing needs of the citizens. This also would appear to be an obvious alternative, given the manufacturing capabilities of China.